First of all, I would like to Welcome you to Pet Talk. It is full of learning experiences and lots of fun... you'll really enjoy it here. My name is Makayla and I own 19 pets.

Your poor dog! Don't listen to your neighbor, he sounds like a total nutcase! I cannot believe he would say such a thing. Nine is so young for a lab to go... they usually live to be at least 12, and usually older. My friend had a yellow lab for 14 years before she passed away. I think you should go for two 20 minute walks a day, but don't overload her with too much excersize. Maybe play some ball in the evening, or if she's not into that anymore not that she has aged, play tug-o-war for a little while, but don't pull on it too hard or yank on the toy or it might irritate her old teeth.
How much food are you feeding her? You might want to cut down on that, too. 4 cups a day is plenty for a large dog if you are feeding more. 2 cups in the morning and 2 at night, or even less. But don't feed less than 3 1/2 cups a day to a lab.

I would love to see some pictures of your girl!