Does my daughter have to wear a dress or can she wear a nice pair of shirt and jeans?

You can dress the way you want Feel comfortable :)

I was in capri pants, top (i.e. not tank top)and sandals and it was fine.

Its casual...

Can she also wear tennis shoes

Nice pants is way good.

I went with my daughter two weeks ago and there wasn't any dress code. She was wearing nice shorts and a T-shirt and everything was fine.