IMDb is mistaken in that Alison Viktorin is "known for" Fullmetal Alchemist: Brotherhood. As was stated in the comments. IMDb simply sees that Viktorin did voice work for Brotherhood, sees that Brotherhood is a very famous title, and assumes that she is well-known for her work in it.
This is quite contrary to the truth, though. Viktorin is credited only as "additional voices" in one episode: episode 43. I've seen the episode a few times, and can confirm that there are only four places where a non-credited voice (i.e. one outside the named cast in the credits) is heard (excluding obviously male voices):
- Two children laughing and playing (2:35)
- Child grabbing Yoki's hair (3:03)
- Baby tugging on sleeve (10:14)
- Unintelligible chattering and whispering (11:01)
Though I can't tell which one of these four instances Viktorin actually voices, all four are very minor roles that are hardly worthy of mention.