Well, not a lot of them are making a lot of noise. Out of the 2014 class of new GOP senators, only Tom Cotton has emerged as a national figure.
That doesn't seem like a good reason for the disparity in assignments. Do they need to be a star to be on the GOP's healthcare working group? Was it to much for them to even include a token woman?
It is indisputable that the GOP has a woman problem both in its voter base and its political ranks. They don't seem to be going that far out of their way to fix it, either.