Anyone know this young adult book?

Question

I read it when I was a kid (we're talking 30 years ago). It was about a brother and sister that run away from home. I don't remember why. Anyway, they end up in a town where I think their family might have a cabin or where they spend summers or something like that. I remember they keep all their stuff in garbage bags including bread and peanut butter and milk. They make some extra money by cleaning for an elderly lady in town and they stay on an island. The description of the shelter they build is very descriptive; they dig a hole and fill it with pine needles, etc. There are some other kids that visit the island, but they don't know the brother and sister are runaways. In the end, they get caught, but the old lady takes them in. I think the last line is her saying that they still have some cleaning to do for her. Sound familiar to anyone?

Sorry, it isn't Gone-Away Lake, but I've read that one too.

Answer 1

How 'bout Ruth Chew's Baked Beans for Breakfast,1970?
From Loganberry Book's stump the bookseller section:
This book is about Joe and Kathleen who run away from their babysitter while their parents are in Europe for the summer. They head for the lake that their family usually vactions at every summer. They go to the country store where the shopkeepers know them from other summers spent there and they buy a sterno stove, a saucepan, a frying pan, plastic utensils, and groceries. They go back a few more times for more groceries. The summer before they had built a pine needle cabin and they planned to sleep there, but it was no longer standing. They decide to go to Epply island, a small island on the lake, and they buy an inexpensive plastic boat to get them there.


PS It was republished as The Secret Summer

Answer 2

It sounds like "Gone-Away Lake" by Elizabeth Enright, to me.

Edit - No? OK, I'll keep thinking about it. It sounds very familiar.