I've had this reoccurring thing every year or so where I remember this book I read in like 5th - 6th grade that was really fucking good every year or so. I need to find it, I try every time but no amount of Googling thin recollections of its plot has got me anywhere.
Alright since y'all are asking for details I'll explain the plot roughly. I only didn't because I've tried this before and it didn't work out on Reddit years ago so I don't expect an even smaller sample size to work but I guess it's worth a shot.
Basically there are 3 siblings. I think they are all female but their might be a younger male. It's from the perspective of the oldest sibling. The are being antagonize by some guy for some reason I can't remember but I think it had something to do with their parents.
Somehow they get their hands on a time book and go back in time to I think around the 1800s where apparently magic was a thing and so were dwarves and elves and other magical creatures. It's explained that the reason these creatures and magic don't exist is because humanity basically genocide them. It's also implied that the guy antagonizing them was partly or maybe wholey responsible. Also the main character the eldest has some magic in her.
Her and her siblings stay in an orphanage or halfway house where she meets a boy and falls in love yada yada. That boy teaches her magic and when the orphanage burns down she saves his life. Turns out that boy was a younger version of the guy that was antagonizing them in the present.
There's also some sort of relationship between life, death, and time or they hold a special sort of power I'm not sure. It is implied that the younger siblings will come into possession of a book of life and a book of death.
That's as much as I can remember I think