Just an FYI, NYC's Chinatown is the biggest in the world. But if you've walked through another good one (e.g. San Francisco, London, Toronto), there's probably not much need to visit the one in NYC. But Little Italy is pretty much nestled inside Chinatown.
It's definitely safe for two women to ride the subway. I've taken the subway by myself for many years now. Just keep your eyes open, as I'm sure you will. I'd also ride it during the day rather than at night, if it's your first time.
Your 16-year-old DD would love the Village and SoHo. Just great neighborhoods to walk through, great little shops, some nice big stores, and even some really nice architecture.
Oh, and you'll love the Broadway shows! I actually preferred Chicago to Wicked, but they're both great.
For anyone who visits Dylan's or Serendipity, don't forget, Bloomingdales is right around the corner!
If anyone has a good amount of time for Central Park, why not try a picnic there? Go to one of the many great gourmet food shops, pick up some nice bread, cheese, salad, fruit, etc., and carry it over.
Other suggestions for Pugdog007's DD:
Go to at least one H&M store. CHeck out
www.hm.com for locations. Trendy clothes at nice prices.
Definitely go to the Museum of Modern Art. I've always loved that place, but I particularly liked it as a teen.
I think she'd definitely like Dylan's Candy Bar (60th Street and 3rd Avenue), plus go into the main floor of Bloomingdales (a full square block, from 59th to 60th Streets, from 3rd avenue to Lexington).
Fifth Avenue, from 60th to 42nd or so. When you hear people talking about the famous Fifth Avenue, this is it. The window shopping alone is great, with all the big designers located there, plus Rockefeller Center (worth taking a peek at it, even if you're not skating).