It willl be up to the State and your sister what kind of sentence he gets. She needs to make sure that she actively prosecutes him. If she doesn't, it is possible that DCF could get involved too and take the kids away for her failing to protect them from him (because the violence happened in front of the kids).

As for the protection, she needs to immediately file an Injunction for Protection against Domestic Violence on both her behalf and the kids behalf, and I would also recommend that she file for divorce.

My office specializes in these types of matters and also offers free initial telephone consultations. If you would like to schedule a free initial telephone consultation for your sister (you could participate too, if it is okay with her), please contact my office at 407-971-6140.