If you were a young woman who had spent all of her youth sickly and kept inside, often in bed, what sort of "what if" bucket list would you write? The list would be compiled from age 9 to 16. Because she is almost constantly with her parents, she is somewhat sheltered.
Is she fairly sheltered from pop culture, too? Assuming not, she'd probably want for the kind of interactions she'd see on tv shows and read in books - sleepovers, going out shopping or to the movies with friends, holding hands / kissing / whatever she can glean about sex from the media she's allowed. There would be health related stuff as well - whatever her condition prevents her from doing, she'd want to do. Playing sports (maybe she wants to try EVERY sport she's ever heard of), climbing trees (maybe there's a tree in her parents' yard that she can see from her window and she spends a lot of time looking at it thinking "I'm gonna get that tree some day), just spending time outside. If she's not very mobile, something as seemingly simple as being able to cook herself nice meal without taking a breather could be on there. If she has autoimmune issues and has to live in a sterile environment, maybe she just wants to pet a dog. Then there's slightly more fanciful or outlandish stuff, like taking a road trip across the country, or flying to whatever foreign country she likes, or seeing Niagara Falls. Maybe she wants to ride a horse on the beach. Maybe she wants to try rock climbing.