Actually, the fact that some memories are locked away may be part of the problem. Obviously with her crappy childhood, she's got some old issues that still haunt her. It'd be a shame to use such an incredible tool (hypnosis) only for play and not for therapy.
As you take her back, talk to her about what's bothering her. Talk her through it, and help her adult self talk to her young self about how she doesn't have to feel bad about whatever happened.
I highly recommend
this page for great information on amnesia versus "reprocessing" memories.