14 Year Old Wants to Be Pregnant

Need advice, what else can we do here?

I (27yo) am helping my dad raise my sisters. One has really good behavior but the youngest has issues. This week she had her phone taken after she was caught talking to multiple grown men. She was sending nudes, saying how badly she wants to be pregnant, and even gave our address out to two of them in hopes of sneaking them in for sex. I found multiple texts saying “I’m home alone tonight you can come over”. She’s never alone for more than two or three hours but I still don’t doubt that someone may have been here.

We are getting security cameras and a gps tracker to put in her backpack. She will also be seeing a therapist and psychiatrist as well as getting tested for STDs.

She missed her period so I made her take a test today and it was negative. I bought an extra for her to retest next week if it still doesn’t show.

Rumors are slowly spreading around the school and my other sister is receiving texts about it

What else can we do in this situation?

ETA: Of Course we have had plenty of sit down talks with her and we’ve done all the educating we can. She is mentally disabled (she has been on disability since she was younger) so we can’t come at the situation like we would with a neurotypical child. Everything we say goes in one ear and out the other, she just sits there with a blank face and then asks for her phone back the next day