please help me find this movie

when i was a kid i would watch this animated tale about a modern like princess who would dance and sing but her father wanted to marry her off. a poor guy from the village loved her and listened to her sing from her castle but there lived an evil older man who made poisonous bonbons that wanted her for himself. i remember there being frogs for some reason and i think the princess had a sister. the poor guy lived in a windmill. the princess had short hair i think.