Udil Eratakuth is listed as being born at the end of year 7, but arrived in the fort in year 6. This save is in year 8, unfortunately, so you can't see where it displayed her as having negative age. Additionally, Dwarf Therapist displayed her as having negative age and size.

Note that the fort is under a Titan attack. The fort is safe, but there isn't a military to deal with the Titan, yet.