Death with Dignity

It might be ironic that today begins the new Death with Dignity act in the State of Washington, just now, when I am up to my eyeballs in dogginess. We have an old Golden named Harley. She is 15 now and I am usually awakened two or three times a night because she needs to be picked up off the floor. I spend the entire day doing the same thing. Often she can't control her poop and so I clean that up too. Arron and I got Harley in London, after rejecting a Jack Russell Terrier for being way too small (at 8 weeks it was smaller than a tiny kitten), and a Scottie dog, known for having crabby personalities. We took one look at Harley and we were lost. We got her and on one of the first days that we were able to walk her in the park after she finished all of her shots, she was brutally attacked by a pit bull (and I barely escaped). They never found the owner and we were left with a £1000 vet bill. She was a mess, but eventually recovered. We were the typical young couple with a puppy and six months later we were pregnant. Harley stood guard over both our kids as they rolled about on the floor grabbing clumps of fur in their tiny fists. She didn't flinch. Carter used to use her as a pillow while he drank from his bottle. When Arron died, she mourned her beloved Master, refusing to go for walks in the park without him. Since then she and I have lived in guarded harmony. I don't think she has ever fully trusted me. She likes men. Can't say I blame her. I have been a pretty crabby Mistress. And now she can't get up off the floor and poops on the rugs. And I am tired. I don't know how to tell when it will be "that time." She still eats her food, still goes for very slow walks around the block with me. But is she happy? or miserable? Is it better to prolong her life so I can avoid what is sure to be hell-blown grief all over again? And what of the kid's grief? Twice now she has bared her teeth at me when I have gone to pick her up. It scared me. She has never done anything like that before (unless devouring a bone). I worry she might do it to the kids. Is it time?