If the Lord really opened it up and allowed that women be ordained to the priesthood, would it be optional? The brethren are expected to receive the priesthood at a certain age, and if they have not, they are not considered to be spiritually "on track" until they have. Their leaders work with them patiently and persistently until they are worthy of ordination. If I said I didn't want to opt in, would I be frowned upon as a less faithful member of the church? Would I be shirking my responsibilities to excecise all the blessings afforded me by the gospel? I hope not, because I would not want that responsibility. I would NOT want the possibility looming over me that I might be called to be a bishop, a stake president, an area authority. My hands are full enough already. I believe in obediently accepting every call to serve that comes through my leaders. If I had the priesthood I would have to be ready and willing at any moment to accept calls like that, even if it meant doing it while my children were still young. Of him unto whom much is given, much is required. I don't think having young children would be any excuse to not be given such duties. If God were to say, okay it's time, we would have to shoulder every call without complaint. I would do it, but please, I'm not ready!
And I don't think I will be in this lifetime. My motherhood responsibilities will not end when my children leave home. I expect I will be a grandma, and my kids will still need my advice, and my babysitting help, and want to have visits from grandma. I know my mom took no greater delight in anything than from doing all those things for us. If I had heavy priesthood duties, I would not be as free to do all those things. I know our families often have to make sacrifices when mom or dad have demanding callings, but really, can't we at least be guaranteed some kind of relief from how demanding it can get?