Hi Skater~
I'm pretty new to posting here, but have had LOTS of turtles over the years. I'm not an expert nor do I profess to be one, I know what I know, ya know??
here's my wooden .05
Sometimes these little guys need you to really keep the food close to their mouth so to speak... I had a really small A.S. hatchling once, that was REALLY stressed from shipping. All it did was lay out on the basking log. It was really weak, and not eating. Anytime I took it off the log and put it in the water~
it floated around the tank for a little while until it bumped into the basking log. After a minute or so it would climb out again and collapse and stay that way. It floated the first few days in my tank too... maybe from air shipping, different altitudes etc. When people fly we bloat too~ your shoes ever feel tight flying??
My resolutions were:
Put the lil' dude in a double big-gulp cup with about a 1/4" of water and 8 good sized guppies. I put the cup on top of the tank in the center support glass so it would get ambient heat from the basking light, but not get too warm or cold~
then I left the room and kept checked in on him/her every hour or so to see the eating progress. Sure enough over the course of the day, all the little fish'eeez were gone.
Maybe try doing a feeding cup and keep the practice up until it's getting stronger and bigger. You might even want to keep it in the cup for a week or two, just change the water daily, rise the turtle in clean water, and add more fish.
If it's still not eating after the first couple of days~ well, you might want to call a reptile vet. These guys do have a mortality rate when they're little, they are fragile despite what they can grow up to be.
Regarless, of the current set-up you have...
Make sure that the water doesn't get too hot 81-83 degrees F. should be pretty comfy.
If it's weak, and not eating, it's stressed or sick~ or both.
Keep the water very clean and keep the water level really low. about 2-3" and over stock with guppies and rosie reds. If it's in a big tank, get into something smaller... a tupperware dish or something like that, so that there isn't a long wait or escape for the food if it wants to 'hunt.' Always have something to climb out of the water onto and a don't let the heat source overheat the water... it's a pet, not an appetizer right?
You might want to also try to keep the turtle in a room
that's realatively quiet until it's chomping freely.
My personal feeling is when they're little and especially little and not doing so hot, you have to be on a less space & water is better for the turtle way of thinking. It take less energy to catch food if it's not running at 110%. It'll only help it's chances of getting back up to snuff. 
Let me know how it goes & Good Luck to the BOTH of you!!
CJ
P.S. do you skate?? I do... bowls, ramps, ditches.