SOLVED. YA Fiction - Girl is transported to a place where no one can lie while looking for her brother or best friend (can't remember). [s]

[Euan]

Read around 2015, possibly on freevampirebooks.com which is now topbooks2019.com-High school girl is teleported to a different dimension where the animals can talk but everyone must tell the truth, I think she is looking for her brother, or maybe her best friend, and she makes a deal with a cat who says she will find him, but without thinking the girl says she will give the cat a favor. I remember the girl also didn't know her dad (view spoiler)[ and it ends up being that he had lost his memory and he was playing the piano for some queen in the talking-cat-dimension (hide spoiler)]. It also turns out that her best friend was from this other dimension as well, I think she sold her memory of her dad to someone in exchange for information on where her brother was. I think the story might start off with the girl not having a date for prom, and I think she took the bus for a long time each day to get to school. This is definitely not in order but hopefully someone recognizes the details. I will add more as I remember them.

[Becca]

Maybe The Iron King by Julie Kagawa, the first book in The Iron Fey series. The cat she makes a deal with is called Grimalkin.

[Euan]

Thank you! I looked that up and that's the correct one!