Wow Momma! You have a lot on your plate! In all honesty, while you don't want your daughter to miss any of those wonderful events that are approaching, her health is more important. Even if she is better and out of the hospital by then, she might still be weak and tired easily. Her immune system might be weaker having battled all of this - do you really want to subject her to the germs that might be lurking around Disney? Just something to think about...Her body is fighting a tough battle right now and it will need time to rest and recover. Release from the hospital does not mean she is 100%.
As for school - I would keep in contact with them and her teacher to see what can be done. That will be tough as well, a lot of work, I am sure, but if I were her teacher (I used to teach!) I would try to be as helpful and accommodating and patient as I could! Maybe there are some things she could send home now that your daughter can do little bits of during her hospital stay? Maybe she can send a textbook and someone can read to her/discuss what the class is talking about so that when the work comes home, she is not so far behind. But again, it is important to remember she is in the hospital because she is very sick and really may not feel like doing school work!! (Can't blame her!) :-)
How old is the 5 mo y/o? I didn't get if she was 5 months or 5 years. Keep strong, Momma! For those babies who are still "cooking", for the rest of your children who need their Mom, etc. I am sending thoughts and prayers your way for a speedy recovery for everyone! :-) Take care and take it easy with the crazy holidays approaching!