Showing Living in Threes by Judith Tarr

Three lives. Three times. Three teenage girls, past, present, and future, come together to solve an age-old mystery and save a world.

Meredith just wants to have an ordinary, relaxing summer. But her mom sends her to Egypt, to help her archaeologist aunt dig up mummies. She expects to be bored. Instead, she finds a greater adventure than she could ever have imagined.

Meru lives in a far-future Earth, where humans travel through the stars in living ships. All she wants is to become a starpilot. Instead, she finds herself on a journey to find her mother and save the people of Earth from a terrible plague.

Meritre is a singer in the Temple of Amon in ancient Egypt. She only wants her loved ones to stay safe. But her gift of foresight warns her of a terrifying future. She tries to find a magical spell that will save her family and friends.

Three girls, from three times, must come together to save their one world.