Hello & welcome to PsychCentral! I hope you find whatever amount of time you spend here to be of benefit.

There is a forum, here on PC, devoted to partners & caregivers of people who have mental illness. Here's a link:

https://forums.psychcentral.com/part...ivers-support/

I'm sorry to read of your difficult situation. Unfortunately, since your bf's daughter is an adult, I doubt there may be much of anything anyone can do to intervene in this situation. As an adult, she has the right to make her own decisions, including bad ones.

Since your bf's daughter is pregnant, I suppose her father could contact whatever child protective services exist in your state to express his concern for his yet to be born grandchild. I don't know if they would be able to intervene until after the baby is born (if then.) But you might at least be able to gain some perspective from them with regard to what is & isn't possible in order to protect the infant.

As far as the abuse you suspect, one resource you might check in with would be the National Domestic Violence Hotline:

Home - The National Domestic Violence Hotline

1 (800) 799-7233

Here again, there probably isn't anything they can actually do. But perhaps they may be able to offer some useful advice.

Here are links to some articles, from PsychCentral's archives, on the subject of how to help someone who won't, or can't, help themselves:

https://psychcentral.com/blog/11-way...-denial/?all=1

https://psychcentral.com/blog/helpin...snt-want-help/

https://psychcentral.com/blog/how-to...essional-help/

There's also a book I have seen recommended as being a "must read" for anyone with a family member who does not acknowledge they have a mental illness & who won't seek treatment. It is titled: I'm Not Sick, I Don't Need Help. (It's available for purchase on Amazon, I believe.) Here's a link to a review of the book:

A review of "I'm not sick, I don't need help!" - Friends for Mental Health

My best wishes to you...