Question about clans and family drama
I'm going to keep this as short as possible because otherwise I'll get a headache.
My girlfriend's mom has always been very proud of who she is and encouraged her kids to be as well, ensuring they spoke Navajo fluently and engaged with community, family, and culture as much as possible. But as long as I've known her she's always been very accepting, she didn't mind her daughter and I dating even though I'm non-Native and a woman, she helped shelter a nephew who came out as gay. She did not get upset about her son marrying a white lady and even attended the wedding which was all the way in NY.
And this lady, lets just say she's my sort of sister-in-law, is a very nice girl who has been doing her best to engage and respect the culture of her husband. GF's bro is a great laid back guy, good at Total War: WH, basically immune to any insult or misfortune ruining his day, never even heard him upset before all this.
Everything seemed okay! Then my gf's bro announced he and his wife were expecting a child in April. We were all happy, my gf's mom seemed happy. Baby was born healthy but with complications for my sort of sister-in-law. My gf's mom congratulated her son and then just out of nowhere hit him with 'it's just a shame the baby's not one of us'. GF's bro is going "why not?" and his mom said since the sister-in-law is a white woman then the baby's basically just a white person since they're clanless.
Bro calls my GF, who goes "well that can't be right wouldn't she just be our mom's clan?". They ask grandma who says that since it's matrilineal gf's mom is technically right but as far as she's concerned the baby's still Navajo. The grandma calls the mom, they get into an argument, now they're not talking. GF is getting increasingly upset, telling her mom that this is her granddaughter and she can't be so cold. We've been helping take care of this baby because sort of sister-in-law hasn't been recovering very well so we're all extremely stressed which I think isn't helping.
My GF asked her mom what would happen if we had kids, such as through IVF, and she said "oh well as long as you (my gf) have it, it'll be fine. It doesn't matter what the father is."
I'm, again, not Navajo myself. But I want to support my gf and her bro and my sort of sister-in-law and my sort-of niece. My GF's dad is of the opinion the baby should be counted as part of the community but doesn't want to argue with his wife and will just agree with her when she's in the room and apologize when she's gone. I don't know what I can say or do to help, besides being emotional support at this point.
This baby hasn't done anything wrong but the grandma basically doesn't see her as worthy of really being in the family. It's like she suddenly realized her son was serious about his relationship with a white lady only after the baby was born.
Is the mom in the right here? Since the baby can't be part of a clan, does that mean she can't be considered Navajo? Where can we go from here? What can I even say?