Older women are habitually treated as marginal figures in the labour force .   I've just come across some figures from the US Bureau of Labor Statistics that really drive home why this should no longer be the case. Here are the key points: 1.  The participation rate for women aged 55+  is already over one-third.  That, if I've understood the figures correctly, is of all women aged 55+, i.e. including centenarians and beyond. 2.  Nearly one third (32.8%) of F aged 65-69 will be in work by 2024.  So much for conventional ways of giving us the labour force figures, stopping at 65. 3.   Nearly one quarter  (22.4%) of…