Welcome to the board! I am sorry to hear about your loss. I understand the need to come to terms with the death of a family member. And for those of us, like myself, who were raised JWs, that is what we naturally think about during a time of grief and loss.
In processing my own JW experience, I was helped tremendously by reading the book Combatting Cult Mind Control by Steven Hassan. I had no idea that the WT was a cult until I read that book (which doesn't mention JWs but describes how cults work). It was very eye opening for me. And since people are especially vulnerable to that kind of manipulation during periods of loss in life, it is important to be informed about it before submitting to a bible study with JWs.
Best wishes to you.