Include

[jordo]

I'm not a "snake person" but since nobody will answer you:
Generally if they have worms they will be skinnier and often regurgitate half digested food, if in doubt a stool sample to the vet can tell you. As snakes get older/larger they will shed less frequently so presuming she is adult it is probably normal for her to shed less frequently because she is not growing as fast.
As for feeding too much or little you haven't said how frequently you feed her
Hope this helps and brings on a few more replies.