She wants to take the notebook of her servant on the grounds that she taught her what is in it
Question

                We have a servant woman working in the house with us, and she is not Muslim. My mother taught her all kinds of food until she mastered them, and she in turn (i.e., the servant) wrote down what she learned in a notebook that belongs to her. 

 My question is: Now my mother wants to take the notebook that belongs to the servant without her knowledge, on the grounds that she is the one who taught her, and she has the right to take what she taught her. Is that regarded as wronging the servant?.
Praise be to Allah.
    Firstly: 

    Bringing kaafir servants and entrusting them with our homes 
    and children poses a great danger to the morals and religious commitment of 
    the children. 

    Shaykh Ibn Baaz (may Allaah have mercy on him) said: 

    With regard to employing kaafir women as servants, whether 
    they are Buddhists, Christians or other kinds of kaafirs, is not permissible 
    in this Peninsula, i.e., in the Arabian Peninsula, because the Prophet  
    (peace and blessings of Allaah be upon him) forbade that and urged that the 
    kuffaar be expelled from Arabia, for it is the cradle of Islam and the place 
    where the Message first dawned. So it is not permissible for two religions 
    to co-exist there, and it is not permissible to bring any kaafir there 
    except in cases of necessity as decreed by the authorities, then he (the 
    kaafir) should return to his homeland. End quote. 

    Fataawa Ibn Baaz, 6/361 

    Shaykh Ibn ‘Uthaymeen said: 
Because a kaafir woman 
    should not remain among you in your house with your family and children, 
    even if the harm is no more than when the family get up to pray and this 
    woman does not pray, the children say: “Why doesn’t this woman pray?” and 
    they love her, so in that case they will think that it is not essential to 
    pray. This is even if she does not teach them her religion, as some people 
    have told us that they heard the servant teaching the children to say that 
    Jesus is God – we ask Allaah to keep us safe and sound. End quote. 

    Liqaa’aat al-baab il-Maftoohah, 
    3/53 

    See also questions no. 22980, 
    26213, 
    26282, 
    31242 

    Secondly: 
The scholars have stated 
    that it is permissible to take payment for teaching worldly skills, and 
    undoubtedly cooking and food preparation are skills that are very important 
    nowadays. 

    It says in al-Mawsoo’ah al-Fiqhiyyah (13/66): 

    There is no dispute among the scholars that it is permissible 
    to hire a person to teach permissible skills and professions which have to 
    do with worldly interests, such as sewing, blacksmithing, construction, 
    agriculture, weaving and so on. End quote. 

    Thirdly: 

    Based on the above, it is permissible according to sharee’ah 
    for your mother to take a payment for teaching the servant different ways of 
    cooking, but she should have told the servant of that before she started to 
    teach her. As for the situation mentioned in the question, the servant has 
    learned how to make food with the encouragement of your mother who chose to 
    do that. She is the one who helped her to do that of her own free will. So 
    it is not permissible for her to take the servant’s notebook in which she 
    has written down what she learned, because it is her property which she has 
    written with her own hand and taken care of. Your mother’s teaching of her 
    was purely voluntary. 

    Beware of mistreating her and taking what is rightfully hers, 
    even if she is not Muslim. 

    Shaykh Ibn Baaz (may Allaah have mercy on him) said (6/362) 
    to one who brought in a kaafir servant and mistreated her: 

    What you and your mother have to do is to send her back to 
    her country. It is not permissible for you or your mother to mistreat her, 
    rather what you must do is treat her in a kind manner while she is with you, 
    until she returns to her country, because Allaah has forbidden wrongdoing to 
    His slaves to mistreat even with regard to kaafirs, as the Prophet  
    (peace and blessings of Allaah be upon him) said: “Beware of wrongdoing, for 
    wrongdoing will be darkness on the Day of Resurrection.” Narrated by Muslim, 
    2578. And he  (peace and blessings of Allaah be upon him) said that 
    Allaah, may He be glorified and exalted, said: “O My slaves, I have 
    forbidden wrongdoing to Myself and I have made it haraam among you, so do 
    not wrong one another.” Narrated by Muslim, 2577. End quote. 

    And Allaah knows best.