I may sound a bit hormonal but I’m not ready to replace my mother in law

My father in law, fiancé bought some clothes for my son who’s due tomorrow. I’m thankful don’t get me wrong but she added a card and signed it off saying love papa and gigi. When I read gigi I started crying. My mother in law passed away two years ago and that’s what my oldest son called her gigi. She drank her life away cause my father in law was so toxic to her. She was literally the sweetest woman I’ve ever met, she was like a mom to me. She showed me love my mom never gave me, did things for me that my mom would never do for me. When my mother in law passed it crushed me. I’m happy for my father in law but I’m not ready to replace my mother in law with his fiancé. My husband feels so bad he gets so angry and annoyed. He wants nothing to do with his dad or his fiancé. (His dad was also toxic to him growing up) He was a mama’s boy. He doesn’t even talk to her. He ignores her. My sister in law hates her but is so friendly with her. Then there’s me I was taught to speak when spoken. My father in law got a new job and moved to another state like way up north we live in the south. His fiancé has to sale her house which may take a year cause it’s old and needs fixing. I can’t wait I don’t want my kids around her. I’m just honestly not ready to replace my mother in law.