Hi SWhite, Generally a plateau is 6 weeks at the same weight. You've already lost 10lbs, so that tells us that your calorie count is probably just about right. I know sometimes after a few weeks we can get more casual with measuring, etc. Your body may also suddenly release several pounds in a week or two and then start moving lower.
If you are staying at your 1400 calories and if you are able to sustain that, I would continue on with your plan. The weight will come off.
You may want to check your salt intake and also some people hold weight longer when they eat too many carbs. I don't believe in giving up any food group, but you may need to tweak things a bit.
Keep walking, maybe adding and additional 15 minutes per session, or walking at least 30-45 minutes each day, worrying less about the distance and more about moving at a nice clip for a certain amount of time.
My guess is that you're generally on the right track and just need to stay committed to your plan. It can be very frustrating!!!!!
Don't forget, you've lost 10 lbs, and that is a good thing.
Congratulations on that!