You may want to consult her first, I'm sure she would know the proper channels to go through to get you in there. And in my opinion you're never to old to volunteer, I still volunteer whenever I here something that interests me, I volunteer at at triathlon every year and it's the time of my life. Also I'm assuming that you'd be working with younger kids, as probably grade 4 and up start to do work and only need one supervisor, you may want to get some medical training, I know where I am you can take CPR classes almost any day of the week.