Here is the original item:
Whenever one of her six cats jumps on the kitchen
counter,
(A) Lorna
just sighs. (B)
And reminds herself that everything tastes
better (C)
if there is a little cat hair in it.
You wanted to do this:
Whenever one of her six cats jumps on the kitchen
counter Lorna just sighs. And reminds herself that everything tastes
better if there is a little cat hair in it.
The comma after counter is correct. You must attach an introductory subordinate clause with a comma.
You might want to review the rules.