Seb's neuro didn't specify his life span but she warned us that 2 things in particular can threaten his life. One is the possibility of his epilepsy worsening as he gets older esp with the onset of puberty. We're already on the lookout for precocious puberty (his brain damage can play havoc with his growth hormones) coz noticed he's developing facial hair above his upper lip. Second is that he's vulnerable to infection, esp lung infection, coz of his risk of aspiration ... infection also brings along fever which tends to lower his seizure threshold. So our stance is no matter much time he has with us, we want him to be happy everyday and have good memories of time spent with daddy & mummy, knowing with full certainty that he's loved, wanted and cherished
It's very normal to have all those worries & anxieties running thru your mind .. . they are magnified in the light of the sudden discovery of your gal's condition. Parents with normal children have those worries too but we with special needs kiddos feel them more acutely coz our kids depend on us so much more. Honestly, I have no easy, magical answers for you but what I can tell you is that all those things can be manageable with you & hubby staying strong & united in your marriage.
As Seb is my only child, I dont't have experience with another child accepting a sibling with special needs. From what friends tell me, the older child takes the cue from the parents and pretty much follows the tone set by them. About her education and independence, I think therapy & early intervention programmes will help a lot, esp with teaching skills for daily living. If Seb, who's so severely mentally & physically impaired, has improved coz of therapy etc, I believe your gal can also improve, given the range of resources available for D.S. children. About finances, well, we've simplified our lifestyle & tightened our belts ... I've traded less pay for more time to look after Seb coz I dont't believe that all the money in the world will make a difference to his world if he isn't getting quality care. But all these ideas & thoughts make up my approach ... you'll soon figure out your own approach that's best for your gal and your family *hugs*