Well, for your daughter with a cowlick, in my opinion, cutting it short with just make the problem worse.
I would say, yes, use pony tails, pig tails, braids, and barretts.
Having six girls I have to say, there are times when you have to get passed what you think is cute and just let them live life and have fun. Hair is so temporary. I have girls that do NOT want their hair brushed EVER and girls that are so flippin' concerned about their hair I want to strangle them with it sometimes. In the end, it really just does not matter so long as they're healthy, happy, and loved. I have two boys that have longish hair--yeah shag...bleh--and two with very short hair. They have to find their way. It's hard to separate our opinions from what's important. I, personally, would prefer to cut all the boys hair short, decorate all my daughters heads with hair styles I like to do and see, and have things my way all the time. It isn't worth giving anyone a complex about. I've done forced hair styles as per my desire but I had children who hated themselves in the mirror, children who NOW are older will NOT allow me anywhere near them for ANY kind of help (peacefully, certainly as Mom I'll go and do whatever I want to, but they will fight, argue, resist, etc...) because of my issues about how they looked when they were little.
At this point, though I don't like the way some of them do their hair I have simple standards they have to follow and we're all happy:
~~You must wash your hair every other day, at least. Except my one daughter who is Samoan, she does it twice a week but still does the shower every other day at minimum.
~~You have to have noticably brushed your hair in the morning before you leave the house.
~~No outrageous or crazy hair styles during the school year--they can put silly colors in their hair WITH ME during the summer
~~Every Sunday for church, or important events, your hair must be respectful to the situation--nothing distracting.
For the littlest ones, so long as I can keep a bow or hair tie in the hair for an hour I'm happy--so, I do their hair JUST BEFORE we go somewhere.
The point is; Your girls are little. Whether their hair looks good or not is a poor indicator of whether or not you're a good mother. The best indicator is how they look at you and how you look at them. Whether they're squeeky clean with a model do or caked in mud with hair matted to their head, a loved child shines through and spotlights a great mommy.
In the end, how their hair looks really isn't that important, unless it's causing them heartache.