Lydia was with me for a while. I was scooting around not paying attention, usually when I rest she shows up.

I ended up playing a bit without her around and I thought nothing of it. Then I rested and rested etc. and she didn't show up. So I went into the console with the idea I would just see where she was and go there when I reloaded. I ended up at Kinesgrove (sp), but she wasn't there. Is this a permant loss?

Nev'mind

If you went to her location and she's not there, it does mean she died and was "cleaned up". Area spells (like most dragon breath attacks) can kill a follower if they've already taken a knee. They don't get targeted any more, but can still take further damage.