Step kids

i am married to a woman which i love and want to be with, trouble is she is using drugs again and staying away from home for days at a time. i have a daughter by blood that stays with me half a week each week. she has two daughters that are here full time. she had a troubled past and lost her kids to dss and she worked hard to get them back into her custody. dss is no longer in there life. i can’t keep dealing with her drug use and staying gone not being here for her kids so i think its best to part ways before it takes affect on my daughter, which knows nothing about whats going on. my step daughters have told me that if i leave they want to live with me and not their mom because they are worried they will be left alone if i’m not here. they are 13 and 14 and i just don’t know if as a step dad if i have any rights to them. what if anything can i do or if i can talk my wife into signing them over to me what would be the troubles that may come with that. the girls have faimly in the area other than their mother but don’t want to live with any of them in fear of being sent to a home of some sort. i would be greatful if anyone can shed some light on this for me

You have no legal rights to her children unless you adopt them.

You have no legal rights to them. You may try and adopt them (if their biological father no longer has parental rights) and have your wife sign over custody after they are adopted.