According to Madhhab:
I'd like to find out if my khalas husband passed away, is he still considered as family and should purdah still be made from him? Also regarding my grandmother, does he still fall under her mahram...
The way that you posed your question was a bit confusing, but our understanding of the question is that if your Khala passes away, will her husband still be regarded as family and what will his relation be to you and your (maternal) grandmother?
During the lifetime of your Khala it will be necessary for you to make Purdah from her husband even though it will not be permissible for her husband to marry you (whilst he is married to your Khala). Thus, if your Khala passes away, then too it will still be necessary for you to make Purdah from her husband as he will be regarded as a complete stranger to you and in fact, now it even becomes permissible for him to marry you. However, his relationship with your (maternal) grandmother is different, as she was his mother-in-law. Due to him marrying your Khala he will always be considered amongst the Mahaarim of your (maternal) grandmother (even if your Khala passes away) and Purdah will not have to be made between them provided that there is no fear of Fitnah.
AND ALLAH TAÁALA ALONE IN HIS INFINITE KNOWLEDGE KNOWS BEST
ANSWERED BY: Ebrahim Patel
CHECKED AND APPROVED BY: Mufti Muhammed Saeed Motara Saheb D.B.
Islamic Date:3 Safar 1440
English Date: 13 October 2018