There is also the possibility that when nesting she got a bacterial infection in her foot. Bacteria can then spread throughout the system and appear in other places like her tail.
This happened once when I used damp sand for a nesting iguana. I use soil now which is less abrasive...
Any swelling should really be checked out by a veterinarian as soon as possible. Bacteria will require immediate antibiotics. Swelling from breaks is best checked out ASAP also...