ok i found some options for you, if the sites will post.
tbh, this all depends on how far your wanting to go with prepping too.
you stated your mother likes the bus right?
well heres a place to buy the used shuttle busses:
http://midamericacoach.com/inventory/1994-ford-e-350-metrotrans
thats a used '94 but they have New and newer used too.
theres also wheelchair conversion kits too if you own a van.
heres some off road wheelchairs:
http://www.mobility-advisor.com/off-road-wheelchairs.html
and heres some natural remedies if you make it to your bug out location:
http://altmedicine.about.com/od/arthritis/a/rheumatoid.htm
as far as the kids are concerned, they're old enough, i aould think, to learn about preppinb themselfs. have them help you create bug bags, and teach them what the idems are or could be used for.
also, you could have them watch videos on youtube, about how to set snare traps, and other useful stuff can be watched there too.
i will keep my eyes out for anything else i can find useful to your situation, and as allways, if you have any questions, feel free to ask.