I'd have to concur with McCaber's post #602 and suppose that it's highly likely that Boro killed Lalaith.
Depending on the Ranger situation - and obviously the Ranger will know best - it doesn't seem unlikely that Nerwen would have been protected last night, or that she would have been targetted. If so then it's still very plausible that we have two wolf-packs still (or maybe not if Lalaith was the last of hers?) Still, I'd love to know what the Ranger's been up to as it might give an indication of how many wolves remain.
I'm babbling. I don't do responsibility well.