Offer her something bigger. After the first meal or two balls are perfectly capable of eating adult mice without a problem.
And just to humor us, what's your setup like? "perfect" is a pretty variable term. Humdity, temps on both sides, what do you keep her in, etc. 
Sometimes balls just go off feed, especially if they're stressed. Maybe she's been handled too much lately, maybe you had a party that week, maybe there's more foot traffic through the part of the house she's in, maybe the moon is in the wrong alignment with jupiter and mars. Leave her alone and don't handle her at all until she starts eating again, maybe that'll do the trick.
Good luck!
~jenny
-----
"The python has, and I fib no fibs,
318 pairs of ribs.
In stating this I place reliance
On a seance with one who died for science
This figure is sworn to and attested,
He counted them while being digested."
~Ogden Nash
jenny.thegreenes.org
"If you're happy and you know it,
Bomb Iraq!
If you cannot find Osama,
Bomb Iraq!
If the terrorists are frisky,
Pakistan is looking shifty,
North Korea is too risky,
Bomb Iraq!
