No, a long toenail won't cause curving toes.
There are several possibilities.. the first is genetic.. maybe it's always been like that since hatch. The second is a broken or injured toe that's already healed. The third type seen is often caused by nutrient deficiency and curls all the the toes more like into a fist.
Is the other side like that?
Currently *sounds* like one of her individual traits more than something to be too concerned about.. according to your description of her behavior.
If you like further analysis.. please tell how old is she and describe feed routine, including treats and supplements.