questions for buddists or those who have studied it

[MonstHer]

I've been researching different religions and I'm wondering about what I came across.
Is it true that women are not allowed to seek enlightenment?
Does this affect anything?
What about buddist nuns?
I am confused...
Is this not sexist?
how do women practice the religion if they cannot seek enlightenment?
Please forgive my ignorance, I am just curious and would like a discussion on this.