He decided to make his first wish for her. But what would he do? He didn't want to hurt Mrs. Wilson, obviously, so he would have to be careful about his wishes and make sure that he could reverse any mistakes he made. He couldn't make her family visit, they were out of range. He could try to wish her up some family nearby. Or he could even make other wishes that wouldn't necessarily make her life better per se, just more interesting. Jon could reverse the wish, so no harm would be done.
Finally, he made his decision.
"I wish that, until I wish otherwise ..." He paused, peeking out the window at Mrs. Wilson and...Sarah McMillan. She was walking down the street. She did that a few times a week. His house happened to be on the road between Melissa Smith's house, and Biff Meadows' house. She often walked the few blocks between.
He watched Mrs. Wilson give a friendly hello, as she did to everyone, and Sarah ignore it. That gave him an idea.