I think that once your child has had ITP for any length of time, you will probably have it in the back of your mind for the rest of your life - I know I will!
But the good news is that 99K would probably hardly qualify as ITP anymore as I think that they they have lowered the threshold to 100. Its a really decent count and although its obviously lower than you would like, its high enough to make no difference to your daughters life. One of the things I've noticed about myself in the time since my son's diagnosis is that my aspirations for his platelet count have lowered. I used to want normal (100+) but now I just hope for safe (somewhere over 30)
Its hard to do, but its probably easier if you don't look at patterns and trends in your daughters count - it will drive you mad. The word chronic doesn't mean much either - it just means its lasted longer than 12 months.
Good luck for Brookes next count
Ali