Is her belly dark in color? That would mean very prenant and ready to give birth. One thing that , helps them along is a PWC and make sure there is plenty of plants,rockwork and decor for hiding. If not, Try feeding shelled peas for the next few days. Platy's love them and that may clean her whistle if she has constipation or bacterial infection. If that doesn't work, isolate her and start an antibacterial like Maracyn. Don't medicate if it's not necessary. The pea's won't do any harm either way.

If the scales are sticking out like a porcupine, it's probably dropsy.

It sounds like dropsy to me to.