So I have a question would you observe your sister in-law and mother in-law with the way they watch your baby before you let them babysit ?

My baby father thinks just because his sister has to kids that it just okay to leave the baby because she knows how to take care of them am I wrong for saying that I have to watch and observe before I leave my baby because I have a certain way I want my baby watch ..his sister has a 2years old and a 1 year old ..

PLEASE HELP GIVE ME SOME ANSWER