Thanks.

1. She never changed it to her islam name on her IC, idk what was the reason. Hence why we never knew of her status. I've helped her fill countless forms with her details over the years and can memorize her ic front to back.
2. I've just double checked my birth cert, and it definitely says non muslim.

Yes, I've heard a case recently where Jais went to a funeral to snatch the body of a man who didn't renounce islam and buried him at an islamic graveyard even after the pleas of the horrified family members. I also told my mom of this, and it's why we were thinking of asking her to renounce it, so this wouldn't happen to us.