I'm not thrilled with the new age bracketing, but for different reasons.
It sounds like the real problem in OP's league is that no one has thought this through. I think OP should voice her concerns to her local league and see if they can improve things.
FWIW, OP, my league has a ladies day league. It is 18+, three doubles. Matches can be on any weekday; there is no particular day designated for the 3.5s, for instance. This is good because even ladies who only get 1-2 days off each week can participate and play the matches that fall on their days off.
The 40+ league plays at night, 3 doubles, 2 singles. Again, we don't have set days of the week for the matches so everybody can find some matches that fall on the nights they can play.
-- Random Error Generator, Version 4.0
-- Master Moonballer