Hi Mom54,
I started WW 3 weeks ago, and since I started running I've had the same problem as you. The first week when I wasn't working out, I lost 1.8lbs, the second week only 0.8, and this week 0.6. I've been following the points very diligently, and so I asked my leader about it at my meeting yesterday. She suggested that since I (like you) have not been eating my activity points , that I may not be getting enough calories. I don't usually use my flex points either, so she suggested that I start by eating the activity points that I accumulate, and if that doesn't work then start eating the FPs, too.
I know it seems counter-intuitive to eat more to lose weight, but I've run this idea by a few friends of mine who have lost a lot of weight on WW. They confirmed that they tended to lose more when they ate their APs and FPs.
Anyway, just wanted to let you know that you're not alone in this particular challenge, and to pass along the advice I received. Good luck and congratulations on your loss so far- 15 lbs is amazing!