Is it possible for a 61 year old woman to lose belly fat?

Yes, with controlled diet and exercise they can. I know that doesn't sound like the funnest way of doing it, but it is the healthiest and its far more rewarding than just paying some doctor to suck it out. Just eat normal portions. Nothing huge, like a steak at Texas Roadhouse or anything. Running also help...well any cardio. So biking could help, and so could skiing (granted you like in a cooler climate). It can be tough, but what's life without a little bit of a challenge right?