Hands down Gracie's is the best in the area. Especially if you want to excel in Tap Dancing.
My daughter took their for probably 14 years. She is no longer with her. She was part of the "Show/Competition Group".
If you just wanna see how your niece will like dance, St. Mary's Co. Parks and Recs has a wonderful program. And, the teacher at the Chancellers Run site is going to begin to offer a Show Troupe through Parks and Rec. They will perform at the local stuff, Fair, and senior centers, if you are interested in that sorta thing. It wouldn't be as pricy as Gracie's and the teacher took for years from Gracie. I've heard nothing but good things about her. I hope this info helps you.