Is she allergic to fish? If not (very unlikely to be) then I'd try some whitefish mixed with rice. She may go for that. Salmon is something that she'd probably eat, but it's very high in fat (compared to other fish), and may be a little rich for her digestive tract just yet.
Chester has allergies to beef, lamb, turkey and chicken, so it's very hard to tempt him with the normal tempting foods, but the fish usually works, and he's not allergic to it.