I mean, unless the population of registered voters is at least 55% women, it's just a fact that the percentage of registered voters who haven't voted yet is going to be more men than women. So there are more potential male election day voters than female.
But beyond that, I'm fairly certain that women are more likely to vote early than men; I don't know if statistics confirm this, but just by nature women tend to be better planners and better at competing tasks early.
Per exit polling 52% of voters were women in 2020. I would be very surprised if we stayed all the way at 55% of voters being women through ED votes. My guess is that it ends up fairly close to 2020. If it's higher than 52%, that would be good news for Kamala IMO.