Need some opinions as to what to do

So I am a mother of two a girl 18 and a boy 11 now pregnant with my 3rd for my husband we are married now for 3 years but when I met him he has 2 of his kids living with him I love all his kids but I don't know how to handle his now 15 years old daughter I have talked to her just the way I would my biological daughter but I don't know if am doing something wrong, my husband, is the type of father who doesn't believe in any type of punishment so whenever she does anything wrong he tries to justify the situation by saying he was the same way so at the age of 14 she started acting out we couldn't figure out why until I start to smell her so I told her dad and take her to the doctor only to find out she contracted gonorrhea that was November of last year now we talk to her about sex and what can happen if you have unprotected sex but that didn't work because in March of this year we caught her sleeping with a boy way older than her in our house we talk to her again even get a police lady to talk to her but that didn't work only for me to start to smell her with that nasty smell again only to find out she contracted another sexually transmitted disease when I question her only to find out she stops at a boy house she met for 1 month house when she coming from school to have sex and they never use condom because they didn't have any I am not from the USA am Jamaican so I believe in discipline my kids I am in the USA now I don't know what to do or how to handle this situation