How about the city parks department? I know the last two cities I've lived in had free concerts with great entertainment.
Is there a public beach or lake nearby?
The zoo?
What about scouts and those types of orgs? Again, if "a little" is too much, do their sponsoring groups have scholarships?
Kite flying - homemade kites are cheeeeeap! We used newsprint when I was a kid, and a torn sheet for a tail.
Dress-up (don't know how old the kids are).
A "tea" with neighborhood friends - kool-aid and vanilla wafers? (again, age?)
It sounds "quaint" (and the kids might balk but it would be good for their little eternal souls): but nursing homes might welcome young kids distributing cheerful cards they've made?
Along that same line, do you have an older neighbor who might welcome some help walking a dog - maybe once a week so it fills time? I'm just thinking that service-oriented things might be good - so show that no matter how difficult things are, we can rise to the occasion and offer help to people in need.
Organize a rummage "sale" - trading out clothes for next school year with other parents?
Plant a garden? One or tow packets of seeds goes a long way (dollar store = 4/$1 now), and the responsibility of caring for the plant makes them proud - and it requires repeated attention that's free.
Just trying to think....
(eta: I really did look for the ages - but only in re-reading did I see them. Oops. Oh well, maybe the young stuff will spark something for someone with littles)
[This message edited by MissMouseMo at 11:13 PM, May 1st (Thursday)]