The kitten food comment was a fact not an assumption.
I'm pleased, she is being fed proper kitten food.

I am also pleased you intend on keeping her safely inside with you. However it is still good to get an inside cat spayed as there are health benefits to being altered and she'll not try to escape your home whilst in heat to look for a mate.

You mentioned you had home for these kittens, which is good.

If any of these homes fall though and you end up rehoming any of these kittens to strangers, please charge them an adoption fee to weed out the weridios and do a home check before letting the kitten go. These points don't apply if the kittens end up with family or friends.

If your local vets are happy not to see your cat, so be it. However it is not standard care, these vets aren't large animal vets by any chance ? (Which would explain the difference in attitude to a small animal vets)