9 year old step child

So my step daughter is horrible! I hate saying that because nobody is perfect but I just can’t take it anymore!!

She’s been suspended from school for stealing multiple times!

She is keeps finding ways to send nude pictures to random boys and men, even though we’ve took away everything she had that’s electronic. She borrows kids from school or steal them.

She sent porn videos to my 4 year old!

I’ve caught her trying to hold a pillow over my 2 year olds face. She said she was just playing but at this point idk.

We can’t get her to clean her room at all.

She’s extremely gross.

She tries to torcher our animals

She does mean things to the babies food if I don’t watch it all times.

I just I don’t know what to do! I’m having a mental breakdown!! Everyone else is treating her likes she just a baby going through a rough time!! Like nobody sees how bad it is but me. What do I do? I’m 26 weeks pregnant, and scared to death to let her anywhere near this baby or the other 2 alone..