I disagree that still training her a little isn't possible........but not if only one adult is sticking to the plan.
Also.......I would NEVER have her euthanized to make my life easier. Never. In fact, I won't euthanize, no matter what. That's just who I am.
I want to thank the others who have shared their feelings and experience with an older dog. It has let me "whine" a bit, and do some self-reflection, and I realize more now that I need to be more comforting and patient with my dog. I love her very much and the last thing I want to do, is be impatient or unsupportive with her in her remaining time here.