Is it possible that this "losing a member of the family" is more of someone who will face a tragic death but come out of it alive, & then just choose to leave the department?
I would almost guess Lindsay, only because it doesn't seem like there's any big story there for her except to be Danny's wife/mother of child. That doesn't exactly fit into a crime show very well. Where do they go with it, & how will it spring into the mix of crime? Just something that baffles me...anyway...
I can see the possibility of Angell too (though I adore her), but at the same time I'm wondering why they would've started her & Flack having thier "relationship" if she was leaving. I guess, in my opinion, it would be like leaving some loose ends for her character.
It will interesting to see who it is, & what comes of it.