She did not do the tawaaf of ‘Umrah because she was menstruating
Question

I did ‘Umrah during the last two days of Ramadaan, but at that time I had my period, so I entered ihram from the meeqaat and did Sa`i between al-Safa and al-Marwah, and I cut my hair, but the menses prevented me from doing tawaf. Around one day after my period ended I did the Eid prayer, and I did the farewell tawaf, and we came back to our country. Is this ‘Umrah valid?.
Praise be to Allah.You did some things right, and you make mistakes in others. You did right to enter ihram from the meeqaat – even though you were menstruating – and you did right to refrain from doing tawaf, but you made a mistake by doing Sa`i and cutting your hair, and you did a mistake by not doing the tawaf of ‘Umrah and Sa`i after you became pure. 
Some scholars regard doing Sa`i before tawaf as permissible in Hajj, but not in ‘Umrah. 
Shaykh Muhammad ibn Saalih al-‘Uthaymeen said: 
It is essential to do tawaf before Sa`i; if he starts with Sa`i before tawaf, he must repeat it after tawaf, because he did it in the wrong order. 
If someone were to say: What do you say about the saheeh report from the Messenger of Allah (peace and blessings of Allah be upon him) which says that he was asked by a man who said to him: “I did Sa`i before tawaf,” and he said: “Do it, and it doesn’t matter”? 
The answer is that this was in Hajj and not in ‘Umrah. End quote. 
Al-Sharh al-Mumti’ (7/310). 
Now you are still in a state of ihram for ‘Umrah, because it was not completed. What you have to do is go back to Makkah and do the tawaf of ‘Umrah that you omitted, and repeat Sa`i once more, and you have to cut your hair after that; the fact that you cut your hair before does not count because it was done in the wrong order. 
The scholars of the Standing Committee for Issuing Fatwas said concerning one who did tawaf without being in a state of purity (tahaarah): 
You are still in ihram for ‘Umrah, if you did not repeat tawaf in a state of purity, and you have to go to Makkah in ihram as soon as possible and circumambulate the Ka’bah and do Sa`i, then shave your heard or cut your hair, and thus you will have completed your ‘Umrah. End quote. 
Fatawa al-Lajnah al-Daa’imah (11/237, 238). 
And Allah knows best.