
I'll move this to solved.

You're welcome! Glad to help. I'll move this to solved for you.

Or more likely
The Fates Will Find Their Way (from POV of neighborhood boys)

Yay! I'll move this to solved and update our shelves.
A Very Special House by Ruth Krauss, perhaps? Illustrations by Maurice Sendak, who was brilliant.

This one fits your description of the plot but not much else:

Also a stretch, but it's a white cover, involves cooking and has something to do with private school:

Possibly TTYL by Lauren Myracle

Nightshade by Andrea Cremer ?

Locked in Time by Lois Duncan

Not an exact match, but Trouble by Non Pratt is new YA with a boy & girl on a bench. (Sorry, on phone, can't link)

You're welcome! Glad we could help. :)
Clone for the link. Glad you figured it out, thanks for coming back to let us know!
Book of Names for the link to first in the series. I'll move this to solved.

Jamie, I'll take care of it for you. For future reference, you just click where it says "edit" next to the message title, and select a "solved" folder. Or a mod will be happy to do it. Congrats on finding your lost book!

No idea, but here's a link to a page in German that lists a bunch of horse books, including a lot for children. Perhaps you will recognize the cover or title.
http://www.detlef-heinsohn.de/pferde.htm (Scroll down to see fiction titles.)