Question Summary:
If someone has a non Muslim sister, can you go pay your respects to the family home?

Question Detail:

Please advise if it is allowed to go to the house of one's sister who has passed away for the funeral. I know we can't go to a church or a temple but if someone has a non muslim sister, can you go pay your respects to the family home? 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh
Visiting a non-Muslim home to pay respect to the passing away of a family member is a sensitive issue. Shariah permits sympathizing with non-Muslims at the loss of lives, wealth, health etc. However, Shariah prohibits a close relationship with non-Muslims. This is to safeguard our Imaan and Islamic values and to save us from compromising with Kufr. When people attend emotional gatherings like death etc, the limits of sympathizing are transgressed.
At times, inappropriate statements which border on Kufr may be uttered, for example, a Muslim says regarding the deceased non-Muslim ‘God bless himher’ etc. which is not permissible. Our advice is to avoid visiting the homes of the non-Muslim deceased. If one is compelled to attend, then one should confine oneself to merely sympathizing with the family and use the opportunity for Dawah. A letter of sympathy may also serve the purpose. The words of the letter can be structured to express sympathy without trespassing the limits and may be an effective way to give Dawah.
And Allah Ta’āla Knows Best
 
Mufti Ebrahim Desai.
www.daruliftaa.net