Ruling on stoning the Jamaraat at night and before the meridian
Question

                Is it permissible to stone the jamaraat before the meridian on the days of al-Tashreeq, because of the hardship and crowding, and I will have my elderly mother with me?.
Praise be to Allah.The majority of scholars are of the view that stoning the Jamaraat before the meridian is not valid, because it is proven that the Prophet (peace and blessings of Allaah be upon him) stoned them after the meridian and he said: “Learn from me your rituals (of Hajj).” Narrated by Muslim (1297).  
The fact that the Messenger (peace and blessings of Allaah be upon him) delayed the stoning until this time, even though it is very hot, and he did not do it at the beginning of the day when it is cooler and easier, indicates that it is not permissible to stone the Jamaraat before this time. 
It also indicates that the Messenger (peace and blessings of Allaah be upon him) stoned them when the sun passed the meridian, before praying Zuhr. This indicates that it is not permissible to stone them before the meridian, otherwise it would be better to stone them before the meridian, so that the prayer – Zuhr – could be offered at the beginning of its time, because prayer offered at the beginning of its time is better. 
Ibn Qudaamah (may Allaah have mercy on him) said (3/233): The Jamaraat should not be stoned during the days of al-Tashreeq until after the meridian, and if a person has stoned them before the meridian he must do it again. That was stated by Imam Ahmad. It was also narrated from Ibn ‘Umar, and it was the view of Maalik, al-Thawri, al-Shaafa’i, Ishaaq and ashaab al-ra’i. it was also narrated from al-Hasan and ‘Ata’. But Ishaaq and ashaab al-ra’i granted a concession allowing stoning before the meridian on the day of departure and he should not depart until after the meridian. Something similar was narrated from Ahmad too. And ‘Ikrimah also granted a concession concerning that. Tawoos said: He may stone the Jamaraat before the meridian and depart before it too. 
Then he quoted the evidence that it is not permissible to stone the Jamaraat before the meridian by noting that the Prophet (peace and blessings of Allaah be upon him) only stoned them after the meridian, because ‘Aa’ishah (may Allaah be pleased with her) said: The Jamarah is to be stoned after the sun passes the meridian. And when describing the Hajj of the Prophet (peace and blessings of Allaah be upon him), Jaabir said: I saw the Messenger of Allaah (peace and blessings of Allaah be upon him) stoning the Jamarah at the forenoon on the day of Sacrifice, and after that he stoned it after the sun had passed the meridian. And the Prophet (peace and blessings of Allaah be upon him) said: “Learn from me your rituals (of Hajj).” 
Ibn ‘Umar said: We used to wait until the sun passed its meridian, then we stoned (the Jamaraat). Any time a person stones the Jamaraat after the meridian is acceptable, but it is mustahabb to hasten to do it when the sun passes the meridian, as Ibn ‘Umar said. 
Based on this, stoning the Jamaraat after the meridian is what is supported by the strongest evidence and by most opinions, and it is more on the safe side with regard to worship, because the one who does that, his stoning is valid according to scholarly consensus. But if a person stones them before the meridian, there is a difference of scholarly opinion concerning his stoning, rather it is not valid according to the majority of scholars. 
With regard to what you mentioned about the overcrowding, there is overcrowding before the meridian too, especially since many people take the matter lightly and follow this weak opinion. 
If you do the stoning just before ‘Asr or after, there may be less crowding. 
It should noted that it is permissible to stone the Jamaraat at night, especially with your elderly mother being there. That is better than doing it before the meridian, because there is no evidence that suggests that the end of the time for stoning comes at sunset. So a number of fuqaha’ are of this view, and it is the view of the Hanafis and Shaafa’is.  
See: Badaa’i’ al-Sanaa’ai’ (2/138); al-Bahr al-Raa’iq (2/374); Tuhfat al-Muhtaaj (4/125); Nihaayat al-Muhtaaj (3/311). 
Al-Bukhaari (1723) narrated that Ibn ‘Abbaas (may Allaah be pleased with him) said: The Prophet (peace and blessings of Allaah be upon him) was asked: I stoned (the Jamaraat) after evening came. He said: “It does not matter.” 
There is no evidence that states the end of the time for stoning, which indicates that it may be done at night. 
Shaykh Ibn Baaz (may Allaah have mercy on him) said: There is no evidence that it is not allowed to stone the Jamaraat at night, and the basic principle is that it is permissible. But it is better to stone it during the day on the day of Eid and after the meridian on the three days (of al-Tashreeq) if possible. Stoning at night is only valid for the day of which the sun has set, it is not valid for the day after. 
The one who missed out on stoning the Jamarah on the day of Eid may stone it on the night before the eleventh (of Dhu’l-Hijjah) until the end of the night; and the one who missed the stoning before sunset on the day of the eleventh may stone the Jamaraat after sunset during the night before the twelfth; and the one who missed the stoning before sunset on the day of the twelfth may stone the Jamaraat after sunset during the night before the thirteenth; but the one who missed the stoning before sunset on the day of the thirteenth has missed the stoning and must offer a sacrifice, because the time for stoning ends altogether at sunset on the thirteenth.  
End quote from Fataawa al-Shaykh Ibn Baaz (16/144). 
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked: You know about the crowding that affects women at the time of Hajj, and they are not able to perform the rituals in some places. The scholars have issued fatwas stating that women may stone the Jamaraat at night. Can a woman’s wali (guardian) go and stone the Jamaraat for himself as well as for her, or should he go during the day too, and only accompany her at night?  
He replied: The correct view is that stoning the Jamaraat at night is permissible, except on the night before Eid, when it is not permissible except at the end of the night. Similarly, on the twelfth he should not delay it until the night (unless he wants to hasten on), because if he delays it until night, he will have to stay until the thirteenth, and similarly the stoning on the thirteenth should not be delayed until night, because the days of al-Tashreeq end with sunset on the thirteenth. It is permissible for people other than women to do the stoning at night, and we think that stoning at night, when it is quiet, and doing the stoning with the proper focus (khushoo’), is better than going to do the stoning by day when he does not know whether he will come back to his tent or die, and he does the act of worship not as a proper act of worship, but he does it in a distracted manner because he is afraid for his life. So we have established a principle that is indicated by sharee’ah: that preserving the act of worship itself is better than preserving its time or place so long as the time allows that, because the Prophet (peace and blessings of Allaah be upon him) said: “There is no prayer when food is ready, or when one is suppressing the urge to urinate or defecate.” If a person is suppressing the urge to urinate or defecate, we say to him: Delay the prayer until the end of its time and relieve yourself, even though praying at the beginning of the time is better; but if you pray when you are suppressing the urge to urinate or defecate, you will not be able to attain the proper focus (khushoo’) that has to do with the act of worship itself. Hence we think that at present, stoning the Jamaraat at night is better than doing it during the day, because when stoning them during the day one cannot attain the proper focus and do the act of worship in the required manner. So it is permissible for a man to delay his stoning until night, so that he can go with his wife to stone the Jamaraat. End quote from Liqa’ al-Baab al-Maftooh (21/18). 
To conclude: it is not permissible to stone the Jamaraat before the meridian on the days of al-Tashreeq, but stoning them at night offers a way out and a solution, praise be to Allaah.  
And Allaah knows best.