Robot Freak RF series

It’s about a 12 year old girl named Una. One day, she runs into Dawn, a ghost scientist, and the next Oceana, a cyclops sorceress. Oceana senses magic in Una and begs her to go to the wall of memories to see if she could possibly be the next sorceress. On the way, Oceana’s sister Roxy tries to stop them. Oceana and Una are always in constant fear of running into Roxy. They won’t know if she would be there the next corner they turn.