Unfortunately, I don't know of any resource besides an attorney that would help with a custody issue. I'm sure that's rough, and I hope things turn out as well as possible for your friend and their family. A few other resources that are outside the commercial realm are:
https://helloprenup.com/ https://hellodivorce.com/ https://www.getdynasty.com/ https://trustandwill.com/
I haven't personally used those services, but the founders are great