yes its the same girl and Amos (the boy from part 1) we find out is her husband. She left the cult because she knows Isaac is deranged and that it cost her her family and her husband.

It's suppose to be the same curly haired girl yes. In this movie Doc Michaels says that Rachel would have went to jail if he hadn't made up some fake paper work to get her out of it. I have some of the props from this movie at home and, one of them is a set of death, birth, and adoption certificates for baby and Rachel Colby. What happened is Doc Michaels forged paperwork that said Rachel and Hannah or "Baby Colby" died during childbirth. This is why Hannah digs up the grave in the cemetary that's empty because Doc Michaels faked paperwork saying she was dead. I hope that helps. So Rachel left Isaac and the children which we learn in this movie and went her own way but still stayed in Gatlin to take care of the children .
It seems the sweet little children of Gatlin have locked the door

She proboly went to the same town all the other surviving kids went to, to be adopted. Or she coulda stayed with Isaac seeing that he wasnt dead

I wonder the same thing. So Rachel is the mother of hannah. Where did Rachel go?