How old is she ? Is this her first season?

Based on her age and shape breeding her could actually kick start her appetite again.

While I prefer my female to be nice and plump (can't really tell for your from that angle), I have also paired females on the leaner side simply because the age was right and they were just female on the smaller side.

Since she has been mainly a mouser I would keep trying with those, probably breed her (again if she feels right) and I would attempt to switch her after she lays her first clutch.

The best type to switch a female to another food is to do so right after they lay their first clutch (they will switch to anything).

Good news is that sporadic feeder can also make a complete turn around after being bred for the first time.