There aren't any woman on the council.
It is common that it is the males of a race that are the ones who travel to work at other worlds as the representatives.
It's universally usual and natural for it to be the males who travel as the representatives of their races.
One race that visits earth has the females as the more prominent sex.
The rest, it's the males.
With that race that visits Earth, it is the females who travel and represent their world to other worlds.
Many females travel in the crews, but it's the representatives who must stay here away from their own homes.
All races value family.
It's natural that it's more often the woman who are more domestic.
The council members are all head representatives of their worlds to Earth.
They stay here to live here to work.
They only go home once or twice a year for a short visit.
Their families visit them here though.
It's just the natural way that fits best for most races.
It's not forbidden.
If the race that visits Earth that is run mainly by their females was on the council, there would be a female council member.
Gender Differences
all races of people are males and females and have those body parts for reproduction.
Advanced races celebrate diversity.
One thing that is the same all over all the universes is diversity.
We are the same that we are all different.
We are intermixing all our genetics on Earth.
Advanced races look very much alike within their races.
One day we will also.
Even males and females look very much alike.
When we refine our genetics for longevity and weeding out diseases, we will be making our bodies more alike across our world.