In my home we always had a box of “house toys” tucked away in a closet (to avoid conflict.) It came out whenever a child was visiting (who was not invited by my child.) I did not expect my child to share her toys with someone she did not know, like and trust. I, and all adults, only share with other adults we love and trust so why would we expect our child to share with a strange child?
The house toy box contained crayons, papers, stickers, blocks, puzzles, trains, balls, and one or two construction sets (Lincoln logs, Lite-Brite, etc.) that could be used by the visitors and my child. She was not expected to share her toys unless she chose to do so.
If, however, she invited a friend to our home the expectation was different. She was expected to share her stuff. Before the friend arrived I would have her put away anything special and /or fragile that she wanted to protect.
Mom and Dad – just remember we only have to share with those we love and trust. It is only fair to give the same choice to your child.