I do think buying a small property for DC 3 and DC 4 is a wonderful idea - if they don't wish to live in it they can rent it out and have a small monthly income. They do need to know though that they need to keep a certain amount in a savings account as they will be liable for repairs.
There are companies who deal with the rental for you and I would especially for DC 4 use on of them so he does not need to worry having to deal with renters himself.
Only 50% of middle age adult manage more than 1 brisk 10 min walk a month.

