What size Hollister/Aeropostale shirt should I wear?

I'm in 6th grade and very short for my size. I'm 5'4 and 59 lbs. I want to wear Hollister. Would the smallest size fit me perfectly, without too much length? Normally, I wear an 8-10 girl's shirt size and 7-8 pants. Regular fits, but slim is better. I dont want to buy pants there, though-just wondering if that info would help! Second-for Aero. I have been to Aeropostale before and the XS is way too long. Do they have anything shorter? My mom doesnt want to spend money to trim my clothes up. If not if i keep growing at the same pace- 1 1/2 inches a year-when will I fit into the shirts? Thanks!