For a seven-year-old girl, I think it's better to learn dance, otherwise it will be difficult to learn when she is older (this is my experience and the reason why I gave up dancing), but it also depends on her talent. If you don't want to learn dance, then learn piano, which may be too vulgar for you, because children nowadays, as long as their parents have money, will immediately let their children learn piano. If other children can learn, so will your children. The sooner you come into contact with these majors, the better. You have to know a musical instrument anyway. If you think violin, erhu and pipa are too difficult, you'd better learn cucurbit or clarinet. These two musical instruments are the best to learn.