Question Summary:
Can my husband be a Mahram for my daughter?

Question Detail:

I was a widow with a daughter & my husband accepted me with my daughter, & after 10 yrs of marriage still we do not have our own kids. In sha Allah this year we are planning for hajj
1) my question is can my husband be my daughters mehram on hajj?
2) before going my husband wants to make a will ,what ruling should be used as he also wants to give share to his sister & her kids which includes 3 daughters & one son.
Does according to shariah law is it necessary to give share to sister as my husband also has 5 more brothers but since his sister lives close by he wanted to give her too. Please advice me on this as all the money is on my name. What share my daughter can get, is she liable to get anything from my husband property? Please answer this immediately as I don't have much time left with the hajj approaching. 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
1). Your husband is your daughter’s mahram.[1]
2). Upon the death of a person, his/her heirs will inherit from the estate. A person’s heirs are his father, mother, spouse, children, etc. Certain heirs may only inherit in the absence of other heirs. A person’s sister falls into this category. However, a person may bequest (wasiyyah) from one-third of his estate for those who will not be inheriting. As such, please clarify if your husband has other heirs (father, paternal grandfather, etc.).
Your daughter is not your husband’s heir. Therefore, your husband may bequest for her from one-third of his estate.
And Allah Ta’āla Knows Best
Hisham Dawood
Student Darul Iftaa
Chicago, USA 
Checked and Approved by,
Mufti Ebrahim Desai.