I don’t want one girl to barely be shown and another one shown too much.
In top of what
RanliLabz already said (and he know what he talk about, he've too many characters and, counting the ones not introduced yet, more than 75% of them are forgot in each episode), I want to add that giving them an equal time will not satisfy the players anyway.
You've five girls, which will lead to way to many combinations of preference coming from the said players. And the less civil of them will complain that "this cow" have too much time while "this cutie" don't have enough ; each one having his own definition of "cow" and "cutie".
Therefore, do as you feel it, let the story decide which girl will have what time of presence. In the same time, keep an eye on the community ; if there's a clear consensus that a certain girl is the best one of the game, try to give her a small place in all episodes. But do this without forcing her presence, the goal being to not frustrate the players, not to completely change the story you had in mind.