My daughter will be five in April, too! Right now, she's involved in soccer and swimming at Emler. Soccer is through the city of Frisco, but I know that the city of Plano has a good youth soccer program. You can also look into joining the YMCA; they have lots of activities/classes for young ones.
My daughter has also done dance in the past and probably will again sometime this year. We've been with a number of places in Frisco, but hopefully, someone can give you a rec for a place in Plano.
As for gymnastics, we've tried a few places but really like The Little Gym on Preston/Spring Creek. My daughter has taken several classes there, and my son is there now. The instructors still remember my daughter and ask about her when my son's in class. The facility is bright and clean, and the instructors are very energetic and patient. The kids learn real gymnastics skill, but it's in a non-competitive environment with lots of support and positive reinforcement. Little Gym also has cheerleading and dance.
Oh, that reminded me that my daughter did cheerleading once at Lifetime Fitness. She thought it was "okay." It was nothing about the class--it just didn't really fit my daughter's personality. But, if your daughter is more outgoing and boisterous, she might really like cheerleading. I've heard that the city of Plano's cheerleading for young girls is much better than the city of Frisco's!
Hope that all helps!