If she is still eating regularly, then you should be ok. Their appetites can vary greatly from frog to frog. They can also vary from night to night. Sometimes mine will eat a lot for a couple nights in a row and then eat very little for the next night or two. It is ok as long as she is still eating good over all and is healthy. As mentioned before, she may have been stunted due to conditions when she was younger or she may have simply inherited small genes.
She will obviously have fewer bowel movements if she is eating less, but it is something you want to keep an eye on. Impaction is very dangerous for them. A five minute soak in some lukewarm de-chlorinated water will often help them go. Keep us updated!