Answered by: Maulana Abrarul H. Hasib
AsalaamAlaikum. My question is what are the boundaries for a daughter in law for her father in law. I understand she is a mahram to him and she can care cook and wash clothes etc for him. Under sharia is she allowed to massage him? Even cut toenails? Father in law is not frail and is still active and working. Are there different boundaries for blood-related daughter and daughter in law through marriage?
In the name of Allah, the Most Gracious, the Most Merciful
The daughter-in-law is a Mahram to the Father-in-law. When there’s a fear of any Fitnah, then she should exercise care and observe the hijab in front of him. 
It is a moral duty of a daughter in law to serve her father and mother-in-law in non-physical services such as cooking, etc. 
Taking physical services from a daughter-in-law is highly risky and fear of Fitnahs (temptations). If any sexual desires arise during massaging, then the daughter-in-law will be haram upon her husband (his son). Hence, any physical services should never be taken from the daughter-in-law. 
As far as the biological daughter doing any physical service is concerned, this is very delicate and sensitive. If perchance, during her massaging of her father’s feet, if any evil thoughts come to his mind (Nauzubillah), then her mother (his wife) will be haram upon him. Hence, one must be very careful and cautious. 
In conclusion, since he is active, not frail and weak, he should serve himself or in the time of necessity, he may take services from his male children and his wife.
Only Allah knows best
Written by Maulana Abrarul H. Hasib
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
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