Thank you very much for your question. It is our pleasure to answer it.

There is no harm if one prays with lac or nail polish on her nails. However, if a woman is going to make wudu' (ablution), she must remove the lac or nail polish from her nails. She can apply the lac or nail polish on her nails after she perform her ablution.

Most believing woman prefer to put henna on their nails; as wudu and prayers, both are valid after the applying of henna.

I hope this answers your question.