As discussed in this question, many ancient Vedic scholars believe that the Vedas declare that it is not sinful for grihastha men to have sex with promiscuous, unmarried women.
This question is now asking whether it is sinful for promiscuous, unmarried women to have sex with multiple partners.
In the entire Manusmriti, nowhere is it explicitly stated that this is sinful for unmarried women. In verses that talk about "unchaste" women and unchastity being sinful, the unchastity is in regard to married women who have cheated on their husband, but since unmarried women do not have husbands, it follows that this injunction does not apply to them.
So is there any verse that states that it's sinful for unmarried girls to have sex with lots of men?