She was one of MIGS' founders, and coached centre manager Lynette Farkash when she was younger.
Farkash was a bronze medallist at the Commonwealth Games at Edmonton in Canada in 1978.
"It [gymnastics] is just what I know" Donaldson said. "I have coached all my life."
She took her fellow Red Hot Lava members, aged from their sixties to eighties, through stretches, a warm-up, posture and balance exercises, and then using the gym trampolines and beams.
"For a lot of them, if they fell it would be a traumatic shock so we are teaching them how to get up, not to panic, so it is not so scary."
Chris Macann (Lady Genibug) thought the beam would be in the too-hard basket.
"I cannot do a lot because I broke my ankle a few years ago, but I ended up doing the beam three or four times, even the big one."
Lady Leadfoot, Barb Sundgren, said the session wasn't just about safety.
"The group believes in growing old disgracefully, being able to laugh at ourselves, letting the little girl come out."