Volunteer that worked at the centre in 2014 told us most extended visitors stayed at Birchwood. WM at that time also used to allow O/N parking = maybe worth checking out as a back up for an odd day or two in between.
FWIW: to others with family being treated under age 21, there is a Ronald McDonald House also.
It Takes No More Effort To Aim High Than To Aim Low - Reach For The Stars