Background Info:

My (long-distance for now) girlfriend and I have been together for one day short of a year as of today, and by now I'm convinced she's basically perfect for me. We hardly ever argue, we are like-minded in every way that counts, and I find her absolutely stunningly gorgeous.

Unfortunately, she is half a country away from me right now (I live and study in New Jersey, while she is getting her vet tech certificate down in Texas), and her family is, to put it politely, not exactly cohesive, and has a long history of mental illnesses and disorders. She is trying to finish up her studies as swiftly as possible while she can, so that she can bail out of TX and come live with me long-term, but for now we are in this awkward intermediate phase.

The only other thing to note here is that she is autistic and the absolute gentlest, kindest person I've ever met. She doesn't have it in her to steal a $1 plushie from a Walmart, let alone get in a fight.

The Incident:

Yesterday, the eldest of her two brothers grabbed and beat her, essentially unprovoked, resulting in my girlfriend receiving multiple bruises and lacerations on her face. He had been antagonizing her for some days prior, mostly verbally, and it's pretty evident from the outside looking in that he is not mentally stable at this point in time.

The attack happened while my girlfriend was on the phone with her mother, and in the full view of at least one other sibling of hers (her youngest brother, IIRC). She obviously defended herself to the best of her abilities, but that was that.

Immediately after the attack, her youngest brother was fully in agreement that she had been attacked unprovoked and that she was the victim. Her mother also seemed to corroborate this (correct) version of events, but told my girlfriend that under no circumstances was she to contact the police about what had happened. When my girlfriend reached out to me, I freaked out and told her to absolutely call the police, damn what her mother said, because I have heard too many horror stories about how quickly and violently DV can escalate if left unchecked.

However, when my girlfriend listened to me and called the cops, suddenly her whole family changed their tune, and was effectively 6 voices against one, all now claiming to the responding officers that she was the instigator, that she was the one who grabbed and pinned her brother, and not the other way around, etc., to the point that the police actually told her that they were considering arresting HER of all people, and wrote down the incident report accordingly.

After this, my girlfriend's mom got absolutely furious and took my girlfriend's phone and art tablet for probably the next two weeks at least (her mom does indeed pay for them, so it's not technically theft, just douchebag behavior on her mom's end). My girlfriend effectively cannot call me now, and can only text me sporadically. She is also absolutely distraught right now, and no longer has an outlet in the form of drawing or calling me.

AITAH?

TL;DR: GF's brother assaulted her, her mother told her to keep quiet about it, I told GF to call the cops anyway, her mother retaliated by getting her whole family to lie to the cops that GF was actually the attacker and by taking all of GF's devices that her mother pays for, and now I feel like our relationship might be in jeopardy and that I did wrong by my gf for telling her to contact the authorities.