Kitten food recommendations

[GingerPCatt]

Our kittens are 9 weeks old but small for their age. A couple of weeks ago we had problems with Elmo not eating a d had to take her to the vet. Since then she's been eating like she's ravenous. The vet recommended Royal Canon gastrointestinal wet food - we tried the dry but they wouldn't touch it.
Were now out of the gastro food and the kittens are eating well. They'll only go for wet food and we need something that will help their growth. Ideally a budget friendly option, but as they're our babies that's not as important.

Elmo is the black one and Remy is the tabby.

Our kitten is 18 weeks now, but she likes the Iams kitten dry food and eats that in preference to the wet. She will tolerate Iams kitten wet in gravy, but would not eat thr felix in jelly!
She had her neuter op 10 days ago and had a pouch of the canin gastrointestinal food you mentioned above which she absolutely wolfed down! I thought because she had been starved for the op, but now I am wondering!
Anyway, Iams dry here and she has gone from 1.6kg to 2.3kg in just under 6 weeks!

Sorry, I meant to add I mix the wet and dry in the bowl to encourage her to eat wet, but you could do that for the opposite reason and get a similar result?