awww- i love san antonio- definately try to get a hotel on the riverwalk- usually we get them through priceline for a decent price. the riverwalk itself is really fun- bring your appetite- there are SO many great places to eat- we ate a place called Boudreax (its sorta fancy but reasonably priced) on the riverwalk and it was awesome. san antonio also had the alamo which is cool to see, the san anotnio spurs (if you like basketball), sea world, and an amusement park (cant remmeber the name)- also about 1 hr away in san marco is a HUGE set of outlet stors which are AMAZING- they have coach, gap, banana, armani, etc- may be too far for you but its amaxing if you get the chance.
enjoy yourself girly- oh yeah sidenote- i was born on the airforce base in san anotnio where you are going to see your brother graduate! have fun!!!!!