The Magic Half - Annie Barrows
Miri is the dreaded middle child, but with a twist - both her older brothers and her younger sisters are twins. She's the odd man out most of the time and now that they've moved to the country she really feels alone. The kids soon learn about a legend surrounding their new house. While snooping around her house for buried treasure Miri finds a strange piece of glass taped to the wall in her room. When she looks through it she finds herself still in her room, but in the year 1935. Once there she meets Molly, a girl her own age who is in desperate trouble. It's up to Miri to figure out how the magic works and how she can save Molly from a terrible fate.

This is one of those books I know for a fact I would have loved as a kid! It has twins, mystery, magic and more. Miri's lonesomeness would have totally spoken to me - a lonely only. And the ending would have thrilled me completely. So while the adult in me would probably only give this about three stars, but it spoke to kid in me so intensely that I'm bumping it up a bit.