Ruby Red by Kerstin Gier

1st in Ruby Red series.  Sequel is Sapphire Blue.  First published in Germany.

Gwen is 16 and lives with her mum, siblings, grandmother, aunt and cousin in an upperclass London neighborhood.  Her extended family doesn't pay much attention to her, focused on her cousin, believed to be the carrier of the time-travel gene that runs through her family and sure to show up very soon in the form of an abrupt trip to somewhere in the past.  But all is not as it seems.  Since a mathematical formula had worked out that Gwen's real birth  date was the birth date of the next time traveler, and her cousin was also born that day, Gwen's mum and (late) father secretly falsified her records to indicate Gwen was born the day before, allegedly in the hopes that she would be able to live a normal life (and since she was born at home with a midwife, no one was the wiser.

Scarlet by A.C. Gaughen

The early days of the Robin Hood story, told from the perspective of "Will" Scarlet.  Known to Robin, John, and a few others as just Scarlet, she is a young woman posing as a young man after running away from an arranged marriage.

Star Crossed, by Elizabeth Bunce

Escaping from Green Men soldiers after a botched theft results in her partner's death, Digger convinces a boat of young nobles to help spirit her away, thinking they are helping "Celyn" escape from convent school.  Willing to leave the city of Gerse behind for awhile, Celyn becomes a maid to one of the nobles, a younger girl named Merista who is about to be presented to the marriage mart, and goes with Meri to reunite with her parents, exiled for the last several years for their part in a plot to overthrow the king and the corrupt church. 

Pie by Sarah Weeks

Alice's aunt Polly, world-famous pie maker, dies and leaves her recipe to her grumpy cat Lardo, and her cat to Alice.  Alice's mother is jealous of her sister's success with pies and people, someone is out to steal the cat in order to get the pie recipe, and suddenly everyone is trying to make pies to fill the pie-gap.  Includes recipes.

SLJ: grades 4-6

The Agency: A Spy in the House, by Y.S. Lee, Bk 1