I never knew radio shack still existed.
Anyways, I dont think she will get her old tama.. Because she has made new ones after her low battery.
Try unscrewing it, find out anything that might be wrong with it. I am sure you can fix it. A new battery may be in order.
For future reference; The type of battery Tamagotchi Connection V3 uses is CR2032. CR2032 is a 3 volt battery and it is amazing that our tamagotchis need such a huge battery.. Anyways.. The CR2032 goes by different names, but it will still work with your tama:
DL2032, BR2032, KL2032, L2032, ECR2032, 5004LC, KCR2032, E-CR2032, KECR2032, SB-T15.
As you can see, try to get a battery that ends with 2032 and it will work. The most common types are CR2032 and DL2032. You can find CR2032 at futureshop and other places