Thanks, guys.
It's been a real help to still have Chopper around (the mutt in my sig pic). He's 10, and from past experience with big dogs, he's probably got 4-6 years left in him (one reason I like mutts, they tend to be much stronger and healthier than pruebreeds).
With Chewy, I can't say I have any regrets. I spent a lot of time with her. Up until the last couple of years, she'd go hiking and camping with me and Chopper. last couple of years she just didn't have the legs for it anymore. But we still played a lot and she was spoiled rotten.
On Saturday, I made the most of it. Like all dogs, she always loves going for rides. So on the way to the vet, I opened my window, and held her in my arms. She just rested her head on my shoulder and sniffed out the window (covering the side of my car with dog snot!).
She really was ready to go, so it was the right thing to do. She went peacefully, thank God.