I am so
very sorry for your loss with Georgie.
I lost our four month old kitten in September 2009 from FIP and it felt as though someone literally ripped my heart out. Although yes, as your vet said, litter mates are at slightly higher risk of developing FIP if another litter mate had it. I agree with Love4himies, animals do know and do mourn in their own way for the loss of their fuzzy friend. I am a paranoid animal mom - if my pets sneeze just the wrong way I panic (ok I'm not THAT bad but you get the idea) - they're my babies and I would do ANYTHING and EVERYTHING for them. Consult with your vet (blood panel would be a good idea) to rule out any issues that may pop up.