It is most likely elderly incontenence, which is very common in older, female labs.
Usually if it is neurological, there will be other symptoms, but have your vet check her out.
There is a product called Leaks No More by Homeopet, available on Amazon.
We used it on our girl when she was old, having the same problem, and it worked well. There might be something as well for the pooping aspect. I would talk to your vet, and she what she recommends. There could be an RX that will help with nerves.
And by the way, our girl was 65 lbs, 15 years and 6 days old last November when we had to help her to the rainbow bridge. Don't let anyone tell you when it's time. She will let you know when she is ready. It's a decision you have to know is right for her, and come to terms with emotionally.
Best of luck to all of you, and wishing you many happy days ahead.