Absolutely agree. My wife ran a girl scout troop for a dozen years and we became quite expert at providing for the less fortunate members.
My #1 clothing source is....the closet. Much of what they already own will suddenly become cutting edge hiking apparel. Walmart would be the second source.
Sleeping bags are the tricky part but since we're in Texas, they won't likely be considering 0 deg bags.
The main thing with the adults is to get their heads headed in the right direction.