I don't know what fleck means either but
I'm 5'1" or 5'2" and right now I'm heavier than you by a lot but when I used to weight about 120, I would either go to the kids section or go to more trendy teenage type stores like American Eagle that carry XS. I still go to the boys for shirts, but my thighs no longer fit into kids

I'm trying to get back down skinny enough to fit into the 28s I used to wear though. I know American Eagle carries down to pant size 28 in store and 26 online, so they're good for pants especially. They also have great polos if you like those. Old Navy also tends to carry slightly smaller stuff. I tend to stay away from Mens' sections in stores like JC Penny because those smalls tend to be gigantic on me, even now that I'm pretty heavy- a small at those places was roughly equivalent to how a medium or sometimes even large would fit me at American Eagle.
Someone said Macy's kid section for formal and I HIGHLY recommend that (or Sear, JC Penny, etc), I got a suit coat and shirts in the kids that fit me PERFECTLY, much better than mens, AND they were cheaper.