KendraKirai said: Unfortunately, explaining it requires spoilers.
She's Apollo Justice's little sister, not that either of them, or even we players, know that until the ending.
I was pretty surprised when I found that out they were siblings (or is that half siblings?), even though it makes total sense once it's explained. I was even more surprised when I found out who their mother is. And I only finished the game like...10 minutes ago? Still reeling from it.
So yes, this is most definitely clever. But really you have to play the game to appreciate it properly.