IC, I applaud your willingness to help your family, my brother stepped up to the plate to do the same after I was diagnosed with 'rotting kidneys' way back in 1983. As it happened I only lost one of them and went on to fly Harriers and even joined the Red Arrows for 3 years all on one kidney. I left the Mob in '98 and joined BA on 747s. Not once have I had problems passing medicals with one kidney. (Having said that I'm off flying at the moment with an overactive thyroid, but that has nowt to do with kidneys!). I have a command course in January on the 'bus, and hope to drag my single kidney succesfully through the course - thyroid permitting,
During my Red Arows days, another team member had prevously lost a testicle in a motorbike crash. The manager would announce 'Ladies and Gentleman, I give you the Red Arrows, 17 kidneys and 17 balls flying in tight formation!'
Edited to say:
Most importantly IC, I was off flying for just 3 months from knife to be being back flying Hawks at Brawdy during my Tac weapons training.