How do I make her bigger?

This is Iris my scissor beak rescue from last chicken season. She should be at least seven months old at this point and she weighs 2 pounds exactly on the dot. Online and according to my vet, she is severely underweight only a month ago was she dying due to her beak getting bad but I took her to the vet and had it adjusted and she’s been able to eat since then although I don’t know if I should continue supplementing with torpedoes (she hates it). I understand that she may never lay eggs due to being so small but I wanna make sure she stays healthy. Is there anything I can do? She’s a very spunky lady.