mtb chick,
You're never too old! Sounds like you do quite well on your bike. To me that says you have good skills, good balance. I doubt that getting the hang of clipless pedals would take you long at all. If you start with the clips as loose as they can be, I don't think getting out quickly will be a problem at all. Climbing steep hills will defintely be easier with clips. If you are riding in a hilly area, taking the time to get the hang of the clips will be well worth your while. I was used to being clipped in from riding on the road so when I started off-road, I could hardly wait to get clipped in. I'm way much more comfortable with my feet securely on the pedals than just sitting on a platform. So it's all in what you are accustomed to. You could get accustomed to clipless.
Then you'll pass even more people!
Time is a companion that goes with us on a journey. It reminds us to cherish each moment, because it will never come again. What we leave behind is not as important as how we have lived." Captain Jean Luc Picard