But Eden wanted Nick to have sex with he r- she knew that was her role, and she wanted to fulfil her role.
He didn't want to have sex with her - obviously because he's in love with June, but also because he felt that her age (15) was too young. Even if that's still allowable in Gilead (or the US), because they were married, he didn't want to do it.
So in many ways he was more coerced into it than she was.
She definitely wasn't raped.