Eventually Sarah decides that making a wish was necessary, but changing her entire family would be too much. Her parents probably would be happier to have been more active in her life and Alexis would probably try to preserve their friendship if she were in Sarah's place.
With that in mind, Sarah considered her words carefully before taking a deep breath and saying, "I wish my parents and best friend Alexis will always be the age they were when I was however old I currently am and that Alexis and I will be as close as we were when we were younger."
After getting that out all in one go, Alexis has to catch her breath as things change around her once again. As the light faded, Alexis found herself relocated to the back seat. In the front were both her parents definitely looking much younger than before meanwhile a 14 year old Alexis was seated next to her.
Alexis was currently telling her mom about some concert the two wanted to go to later that summer, which mercifully gave Sarah a moment to process the new memories before she had to jump into the new status quo. She was relieved to find that her life matched up much better. Obviously some things weren't exactly right, like now she remembered having a crush on Alexis' 18 year old brother, Michael, which was especially strange since originally that was the other way around.
But considering her relationship with her parents and Alexis was correct, she was willing to accept those kinds of oddities. Her mind was still a bit muddled on some specifics so she couldn't recall whether they were still heading to summer camp and whether she and Alexis would be counselors if they were. Would two girls who just finished the 8th grade even be eligible for something like that?