I'm many years older than 20!! I found quilters in my local guild to be closed to "newcomers" (I was about 55 when I joined the guild) so I quit attending the meetings, and it had nothing to do with age. I am more of a loner and introvert anyway, so I actually do better on my own.
I would encourage you not to give up, however. Look at Leah Day, her skill, and her age - 27 or maybe 28. She commands great respect for her quilting skills. So even though you feel age is a factor, and it certainly may be with some women, stick with it. Don't become discouraged. You may be the next Leah Day!!