Can a woman lead other women in prayer?

Yes, this is fine. We know that Aisha used to lead the female companions in Salah, so the prayer is valid. Specifically in the Hanifi Madhab though, it is preferable to pray alone because in the Hanifi Madhab, Aisha wasn't a regular thing in terms of leading the other female companions. So in the Hanifi Madhab, it's preferable to pray individually, but if you're to pray in Jama'at collectively, there's no issue with it, then the Salah would be valid.