What’s up with Grace and Christopher Lightwood being married in the family tree? I’m confused and worried! — timelord-amypond
There’s no reason to be worried!
The family tree is meant to be a ‘found object.’ Meaning that it is supposed to be created by a person, so it isn’t a piece of objective truth.
There are reasons for pretty much everything in the family tree. But some of the marriages are arranged/faked, some of the people marked as dead became mundanes/Downworlders, there’s a reason the Carstairs records have been destroyed, etc.
You can’t, honestly, predict the plot of The Last Hours by looking at the family tree. So even though it is a fun thing, don’t let it give you grief. By the end of the books, you will understand why even the things in it that are not true were written down as they are.