Hiya!

natures menu kitten food is good, you can get it from pets at home its 65% meat and doesnt contain the harmful fillers that the majority of cat food does. I would wean her to a different food, dont ever change food drastically it will upset her. The worming has probably upset her tum too.
I have to say Royal canin is not good, my cat was on that and felix (4% meat!!) she has very smelly loose poo, its taken me 7 weeks to wean her off them and shes 100% better.
Dry food generally is not great but if you do use it orijen or
OrganiPets Organic Pet Food