Ive had sex with an 18 year old girl and I cumed in her. Im 15 but if we have a baby can she go to jail? In the state of houston?

Yes, she can go to jail for molesting a minor.

Yes, you're a child, she's an adult, she could be charged as a sexual predator and go to jail. She'd also be on the sex offenders list for the rest of her life, and may not even be allowed to keep her own child, or be around anyone elses child.

That's what happens to child molesters.

Yes it is possible, there is no reason a 15 year old can not father a child. Yes it is possible that she could be arrested.