Fantasy quest, split history, kids in tow

[nightdreamer]

Been trying to remember this book for some time. There was this woman who had been a member of some kind of order. There had been a confrontation with something evil in a tower, and two differing accounts of what had happened. Turns out in the end that history had gotten split and two different things HAD happened. But what really stuck in my mind was that because her husband had abandoned her, she had to embark on her quest to set things right with her two kids in tow, which still strikes me as unique. I'm thinking "crystal" appeared in the title somewhere but searches have failed me.

Sound familiar?

 

[yodachan]

Caught in Crystal, by Patricia Wrede, part of the Lyra series.

 

[nightdreamer]

Yep. That's got to be it. Thanks so much!