It can be hard to accept other people's help, especially when they're do-gooders like it sounds like you have in small town Appalachia there. I'm glad you "like" the school social service person, I'd try to work with her more or get a group of them together (her and the teacher both) and "educate" them :-)

I think if you stay in contact with them and communicate, it might go smoother and they'll get to know you a bit better and won't have to resort to shots in the dark as to whether you need/can afford tooth paste. It sounds like they're not quite sure what your needs are, having only talked to your son so far (obvious first place to start since he's the one with the school problem and they're there at school); talking to the social worker and sounding "efficient" in your thanks and laughing at the toothpaste (tell her you have no place to store it you have so much you bought on sale last week at Walmart? :-) and tell her the "mold" is actually a bit of mildew (small lie but not as scary sounding to health-conscious do-gooder social workers) and that you were carrying on about it and your son heard, etc.