does she have blu eyes? or does she ha s blue eyes? which is right? why?

you can remember this way. i- have you- have we- have he- has she- has they- have singular - has plural - have

Does she have blue eyes ? Is correct. Here "have" is used as a main verb so we should not use "has" in this sentence. She has blue eyes. In the above sentence, "has" is used as a helping verb.