Debbie I am so glad to hear of you. When we were in Grand Teton 2 years ago you were not there (Sara knew ) but we are jealous to hear you can go there every year.
I am so sorry to hear about Cracker jack and Robin. Jackie will be ok for a long time because blindness is nothing that gets a kitty out of his comfort zone - I am more worried about little Robin girl. I feel it is too short after your last generation to be with senior kitties again. I think you are taking the completely right decision to let her have a happy and spoiled life as long as it lasts.
One of the food things Filou loved when he ate little else was egg yolk. It is full of healthy fats so maybe you can get the girl to lick one once in a while.