TBH, I am a lesbian myself, , traditional marriage is obv out the question. I know 3 couples who got a 'civil partnership' in the civic hall, and they went down the alter together.
The walking down the alter think (traditional), puts one member of the relationship above the other, so most don't do that, as both partners are on the same level.
The reason the man waits for the woman, is that it signifies the woman giving her live to the man, as she approaches him. Women used to be used to have and keep the family, and the men were the boss. So it really doesn't apply to gay couples in that way.
I don't know. I think it would be cool if they walked down the aisle together, or maybe each walked down the aisle separately, like one walks up to the altar, and then the second one follows... I don't really know of any lesbian marriages that I could refer to though.