Experts agree that there is no "right way" to respond to sexism or to deal with sexual harassment and abuse. You do what you have to at the time, and children will feel more confused and less confident in speaking up, in general.
But yes, our collective silence does send a message to girls, younger women and men of all ages.
Although I always say there are no "shoulds" when dealing with this BS, I have one exception - We should be able to stand up to sexism, speak up for ourselves and call out dangerous attitudes, without being made to feel guilty, embarrassed, ridiculous etc etc
It's gonna take a while, and we'll have to get comfortable with being uncomfortable. There's always backlash because other people don't like confronting these issues and speaking up forces them to do that.
Tough. If other people (including family members) don't look out for us, we have to do it for ourselves. Time's up on always putting ourselves last.