u/Flashy-Outside-2702

My niece (12) was removed from her father’s home and put into foster care two years ago. Both of her parents agreed to sign over legal and physical custody of her to me (32) about a week later. They indicated they will not pursue custody of her again. Her father has supervised visitation rights. Her mom (my sister) does not have any formal arrangement. I want her to have a relationship with them, but do not think either of her parents will be able to provide her a stable/healthy childhood.

Should I consider formally adopting her? I’m unmarried but am in a long term relationship. What would happen to her if something happens to me?