Because she can't move around without giant pieces of gear! I mean, she could combat crawl... But that's probably not the best option for a fifteen year old!
Most of the time, Katherine uses a giant power wheelchair. I'll talk more about it later in a different post, but for now what you need to know is that it weighs almost 400 lbs. It is about 2 feet wide and almost 3 feet from toe plate to back wheels. This machine improves her quality of life in so many ways, although I am not a fan of what it does to my toes, walls and furniture.
Katherine is a very good driver, but a wheelchair just takes up a lot of space. Especially a power wheelchair, and especially when it is driven by a teenager with less than perfect eyesight.
We haven't been using it at home yet, but Katherine does also have a walker. It too takes up a big footprint, and requires a lot more effort on her part to go the directions she wants to go! Also, a lot more effort on our part to get her all strapped in and going!