SOLVED. YA/kids' sci-fi, time travel, set in future

[Kathryn]

Hi! So I read this book somewhere around the early-mid 2000s. It had a female protagonist, I think teenage? It was set in a semi-dystopian future - I want to say that the protagonist travelled on some kind of glass tubelike public transport, but I might be misremembering that. I think she had some kind of fake/robotic pet, because animals didn't exist or just weren't kept? Her house was very futuristic, control over what the walls displayed etc, and maybe verbal weather reports from the house when she woke up.

Somehow she travels back in time to pre-historic fish times, and I think the people then called the country Albion. There might have been something to do with a cave with the time-travelling. I think there was some kind of romance in the past, and I think she ended up back in the future, possibly travelling more than once.

From what I remember, it might have been part of/the beginning of a series, and there was something about mirrors in either the book title or the series title. It was either for teens or pre-teens. I read it aged around 11 in my school library.

Thank you in advance if anyone finds anything, this book has been at the back of my mind for ages but I just can't find anything!

[Kathryn]

And of course I found it a few minutes after posting this! It's Breaking Through by Louise Cooper :)

[Bargle]

Clicky for book.
Breaking Through by Louise Cooper