Moving back to be near ex

Hi there,
Asking for my little sister, we are all very concerned. My sister fell pregnant to a guy she had been with for just a year, they were both only just 20. I'll make it easier, sister is L and the ex boyfriend is A. We were a bit concerned as we didn't know him that well, his parents and sisters were quite nasty to L. Just confrontational people, like drama - very different to our family. It was a small town and the family were sort of known as being obnoxious and pretty "mouthy" (as described to me once). Anyway, long story short, lots of things happened, A lost his job, didn't want to find another where they were living so moved back into his parents with L, they didn't have to pay rent there while they sorted things out financially.

From what L tells us, he has always been a sook, throws tantrums, will go off over literally nothing - didn't know him that well, we all lived a decent distance from her. Anyway, an incident happened where she called our other sister crying that he pushed her out of a car and tried locking her out of said car, in the pooring rain to keep her away from the baby. What started this is she found a dating app on his phone when trying to add herself on his snap chat. My other sister lived 3 hours away and by the time she was half way there they were sorting it out. Our sister went and saw her the next day and said her legs and arms were covered in bruises.

It's now 4 months later and she just broke up with him after he shoved her repeatedly into a wall all over her finishing work, and asking A to give the baby a bottle when he "had him all day", and couldn't drag himself away from the tv. She said she cracked the shits and said he needs to do more to help, and he responded by screaming at her and pushing her. His family were all out at a Christmas BBQ. Anyway, big explosion happened between them, police were called, L got an AVO on him as advised, and Mum took her home to Vic, from NSW. L got permission to leave, but we are worried she will eventually have to move back to NSW to be closer through the courts. His mother told L that they will fuel everything they have into getting custody of the baby, and made lots of threats about it before she left.

Can anyone shed some light on the likelihood that she will have to move back in that direction? She has no one else there, no support, no friends, no family. We are all here in Vic. L literally does everything for the baby, last time I stayed with them for two weeks, I don't think I saw A touch him once, and I was pretty concerned about that. She is willing to drive bub half way, every second weekend after a court order is in place, she doesn't want baby to miss out on seeing A.

She is really quite depressed about the whole situation, and we don't want her to be isolated down there with all of his family carrying on like they do. As I said, very small town, very obnoxious people.