Oh, dear... you've got a Mary Sue. A few tips, just because the Mary Sue badness is consuming what could otherwise be an entertaining and clever story. Firstly, you singled out one character in a dozen, and immediately gave her an unusual, sexy trademark outfit. Most people have to be successful before they go about making a trademark, but Danielle just walked in- not wanting to be an alchemist, as a matter of fact- but had not only a trademark, but a deep, dangerous secret (the gloves) and apparently quite a bit of power. It's out of character for Roy to force anyone into a career they don't want, let alone his own niece. Mustang manipulates, but he doesn't force. You gave your character a lot of guts, selflessness, and a temper. Coupled together, you get a fierce, utterly heroic, and wholly cliched warrior. On their own, or with a counter-balancing flaw, these traits can shape a good character, but without a flaw, you've got a Mary Sue. That temper ("Am I dead?" etc) is just about the worst cliche in the Mary Sue world. Everyone's got it, and quite honestly it's a little sickening. Add in the relation to a canon character- Mustang's niece- and, well... She's hot and powerful and teh gurlpower YAYNESS mrowrrrone!eleven!!11! but Danielle killed the story. Period.
Wish you better luck with your OC's in the future.