She is in her 60's and she does this
I don't mean to be rude but I don't see how you can see this and not separate the sentiment with the talent of the performance. The entire song is a testament to an older person not being hindered by their age, and Martin's performance on the trapeze is exactly that. It isn't just a talented acrobat performing tricks in the middle of a song, it is a woman many people in our culture would consider past her prime performing incredible tricks. I think it more than fits the song's message.