Seventh Heaven, a quilt shop is on New Braunfels street--great shop!
McNay Museum is very close to the quilt shop and this is another great site.
Witte Museum is on Broadway about 2-3 miles from the Riverwalk.
Quarry Mall is north of Riverwalk and is truly awesome. If you like Italian food, try Paseano's. One of their best meals is Shrimp Paseano--very yummy!
Lots of restaurants on the Riverwalk. Also Rivercenter Mall has tons of stores.
If you can get north of San Antonio to a quaint German town named New Braunfels, there are two quilt shops--Quilt Haus and Oak Leaf.
You could "visit" San Antonio for a month with still stuff to do.
Contact me for more info if you need it!