My dd is nearly 12 months old but I've been giving her cheese sauce since she was about 8 or 9 months and she absolutely loves it, in fact, if I can't get her to eat her dinner, I add it to her food and she gobbles it all down. It's really easy - I use Annabel Karmel's basic cheese sauce recipe:
15g (0.5oz) unsalted butter
15g (0.5oz) plain flour
200ml (7 floz) full fat milk
40g (1.5oz) cheddar cheese, grated
Melt the butter in a saucepan, stir in the flour to make a smooth paste and cook for 1 min. Gradually stir in the milk, bring to the boil and cook for a few mins over a low heat until thickened and smooth. Stir in the grated cheese until melted.
I usually double the amounts in this recipe and freeze it in 2 tbsp portions.
Good luck!
Shanaz