Escorting a bride down the aisle is not a mandatory part of the Catholic nuptial liturgy, but is a custom that is allowed. Although this social honor traditionally goes to the father in Christian weddings, the honor can also go to both parents, to the mother, or to another close relative or friend (and is not an honor restricted only to Catholics to perform). I would only say that the honor traditionally goes to someone who has participated in the rearing of the bride, so it might be more appropriate for you to walk your daughter down the aisle.
As a side note, I should also mention that this custom should not be confused with “giving away” the bride. “Giving away the bride” is an additional custom in Protestant weddings, traditionally performed by the father after he has walked the bride down the aisle. Because Catholic marital theology indicates that the bride and groom must freely give themselves to each other in marriage, Catholic weddings omit any question asking if someone “gives this woman to this man.”
