I am not sure about age, but you are never too old to excercise and get rid of those old lady arms.
First, do some yoga- I reccommend the earth flow basics. Stretch out your body and get it in workable, moldable shape. Next, get into a regular routine. Small weights and high reps will burn the most fat and flab. Now, if you are up for it, get a video or get a gym membership. I like turbo jam. It has a low impact version that they show you for people with sensitive joints- which can be anything from age to vitality to weight causing an issue. Also, I think they are called zumba classes, but I have a friend who decided her severe overweight issue needed to be resolved and loves zumba. All excerise will burn fat, all over. The weights on hands and arms will focus a little more energy on the "problem areas" and keep you going.
If you have a hard time staying motivated, get a friend to do it with you...and go outside a couple of times a week with hand or arm weights and ankle weights and power walk with a friend. You will immediately start to feel better.
Hope this helps
-E. M