If she's been pooping regularly, it's not an impaction. A nice soak still never hurts though, mine seems to really enjoy them.
I would guess she'd start eating more regularly if she was on a mostly insect/worm diet... Just a warning though, try to stay away from goldfish or rosy red feeders. They have an enzyme called thiaminase in them that can keep many species from processing vitamins correctly and lead to some really nasty neurological problems. I'm just paranoid because I raise garters, and they are more sensitive to thiaminase than most species... I don't think they're as overtly bad for pacs, but it's just something I try to stay away from.