Yeah, this sounds exactly right. Your friend needs her fear of others to be re-calibrated, basically. Ultimately, crimes like those are fairly rare, especially considering OP says she "lives in a decent area". When something like this happens, it completely fucks up your barometer of things to be worried about.
The big, shitty thing about anxiety, is that it reinforces itself. It's easy to think that things are only going well because you spent so much effort making sure they work out alright. In actuality, they would have been fine, and you spend hours limiting yourself for nothing. Sure, we all know locking your doors at night, locking your car doors, and not walking home alone are probably good practices. The thing is, 99% of the time? They probably don't matter, and if someone really wants to harm you, they will.
Her therapist isn't worried about her locking her doors, he's worried about her developing a compulsion to lock and unlock her doors every 15 minutes. He's worried about her ONLY going out if she has someone right there with her. He's worried about her deciding to sell off her car, because "otherwise someone could steal it".
She needs to reset her barometer before those actions start sounding reasonable. Before her diagnosis becomes something more serious like agoraphobia or obsessive compulsive disorder.