My little Penny passed away last night

I don't know if the KC put a strain on her already weak heart or she already was in the last stages of heart disease. She had a severe heart murmur. I hope it wasn't the KC as she got that off Alfie who got it at the vet and so I feel mad at the vets.
I had just figured out what food she liked too. She lover all the ingredients made into a meat loaf and went to the shop yesterday to get everything to make some up.
Alfie is doing well except for missing his sister.