All four of my girls were obvious as babies- my youngest is 1 and I know she's right handed because when she eats ect she favors her right hand. By that age my oldest child was primarily using the left hand. She is now 5 1/2 and still using the left hand.
All children do use both hands to color with to some degree until they are a certain age (usually about 3 or 4) but if she's showing NO preference I would be concerned. There's a disorder that is certainly treatable but the main problem is the inability to cross the midline point. If she is coloring with her right hand and wants to color the left side of the picture, she may change hands.
They have found using ultrasounds that even babies in utero have a preference for a certain hand and almost always are clearly right or left handed by 24 months. So by observing your child eating AND drawing AND playing if you STILL don't see an obvious preferance you need to call Early Childhood Intervention. They will do a free evaluation and often in home therapy is free as well. This is only till she is three, though, and then you have to look into the school system for help, so it should be looked at as soon as possible.
Blessings, S., mom to 1 in Heaven, 4 on Earth and 1 "deep in the waters." My girls are on the autism spectrum, and problems crossing the midline can be a comorbid syndrome of autism which is why I know about it. I also have a certificate in child development. :)