I wasn't sure this was about sulcatas. I suppose they're
calling m/f just for convenience because there's no way to
know that for a long time yet. Anybody (especially if the
breeder said this) that says they're sexing hatchlings is
full of nonsense and if the buyer thinks this, then they
need to research sulcatas quite a bit more. Most of these
"females" wind up males, and two males is often a nightmare
in itself.
As far as feeding, I'd give a recovering animal the benefit
of enjoyable foods, eventually going to a stricter diet.
I know they often adore bananas (just a pinch) and green
peppers (mine loves these), yellow squash and zuchinni squash.
For a hatchling I'd recommend repti-cal and herptivite just
a matchhead size pinch of each on every feeding as a supplement
and later go to cuttlebone.
When you soak it, put it in a container it can't get out of,
in lukewarm water shallow just to the shell height under the
head (gulars). Make sure the water doesn't get cold, which happens
fast and dry thoroughly. Don't leave them alone in case they
flip or try climbing the container and fall out.
Paper towels is a good substrate for sick/recovering animals.
After that, I'd to to Lizard Litter Kenaf Plant, the light colored
lizard litter, I found tons of it at another pet shop here also.