I've never seen any cycling stuff at TJ Maxx. They seem to have a lot of Nike and Addidas stuff, and not great choices there, either. I have one running type long sleeved top and a pair of pants I got there. Not too great of a chance they'd have an extra small, either! Heck, I can't even buy regular clothes there.
This is weird, but in the late eighties an REI opened where I used to live in AZ. I bought a pair of what I thought were "aerobics" shorts off the sale rack. I must not have tried them on, because when I went to wear them, there was this weird "pad" in the shorts. Little did I know that they were cycling shorts! But, I wore them for years, because of the way they flattered my body. It must have been my first experience with lycra. I think I had an inkling they were for riding, but it seems strange now.