Changing from kitten to cat food Royal Canin

Our Scottish Straight Belle is now nearly 11 months old and 4 Kg , She was slow starting to eat the Royal Canin British Shorthair Kitten product but has eating it happily for months so we decided to try the adult  version and .... she is refusing it again. I have tried mixing it with the kitten food - she picks out the kitten food and leaves the adult. I have tried mixing it with the wet puches she also eats and she mostly leaves it but will sometimes eat a little, I have even cut the pieces in half in case it is a size thing and she does sometimes eat it so what do I do?

What if I keep feeding her the kitten food?

Do I press on and hope that one day she will be hungry enough to try it?

Any other ideas? I emailed Royal Canin but the very nice US rep said they don't carry the kitten food and would put me in touch with the UK and Ukraine branches bjut no answer from them (thanks guys)

TIA

Paul Alina and Belle in Kiev Ukraine

Can you post the ingredients list of both the kitten food and the adult food? "Kitten" foods aren't usually any different than adult foods other than they tend to be higher in calories since kittens are growing rapidly. Perhaps the kitten food is higher in fat and she likes the taste better. There are a lot of foods available out there, you can likely find something she likes but I'm not familiar with what's available in the UK, however Royal Canin isn't really great food so perhaps someone else can chime in and give you some options. It's also not necessary to feed kibble. If she doesn't like kibble you can put her on 100% wet food.