L.C.
I'm sure she is fine, all babies go at their own pace and they are all different.
That being said, at five months the stretches should start to go a little longer than two hours. Others may not agree, but if it was me I would try making her wait a little more each time (very gradually). This will also cause her to be a little more hungry and she will eat more at a time which will in turn enable her to go longer again. It is a good cycle to start. Also, she may be just about ready for some solids to be introduced within the next month or so. If you started giving her a little bit of rice cereal mixed with breastmilk before feeding time it would help her to go a little longer and give her some mass for her poops.
You can also check with your local La Leche League about any breastfeeding questions. Just google them.