@Cutie pants She didnt want something fun, her parents and Eris dad naively thought marriage (and eventually kids) would BE the "fun" that got her to find any meaning in life.
As for the why: the same reason most people do anything in these times: its what was expected of them. She knew what her societal duties were, she just didn't care about them enough to have an opinion. It's like a train following tracks, she did what was expected without any real thought because she simply did not have the capacity to.