Elphaba - I am so sorry to hear this. Somebody broke into my mother's house two years ago and stole her jewlery, credit cards, and just ransacked the place.
It is a traumatizing ordeal, and took my mother quite a while to feel safe again. We put in an ADT system in her house, they have been fine. Make sure to use an easy number for your mother to remember for the alarm code... it took 2 trips out by the police before we decided to use her birth year!!
Personal safety, I agree with shakran... it sounds like your mother is probably too old to learn much that could be effective, and unfortunately the classes have been known to instill a false sense of security that can be dangerous in the wrong situation. Rather than pepper spray or any weapon, I got my mother a loud horn that fits in her purse. Studies show they are just as effective for warding off the bad guys, and it can't be used against her.
I am glad your mother is safe and has lots of family to lean on - and I hope the punks spend a little time getting "mugged" in prison themselves.