Originally, however, a mission wasn't something Smart said she was sure she wanted to do. Even when she was at the Missionary Training Center in Provo, she continued to have doubts about whether she had made the right decision. It wasn't until a man she had once dated — whom she clearly told it wasn't going to work out between them — made an ill-advised marriage proposal inside the MTC that Smart knew going on a mission was what she wanted to do.
https://www.ksl.com/?nid=148&sid=15656348
That made me laugh. Guy clearly can't read women and might have some mental problems to boot , but you have to give him props for trying in the MTC. That's a pretty gutsy place for a proposal.
What this appears to be is just a jealous harlot upset over their polygamous marriage. No doubt Elizabeth felt a bit betrayed by having her husband favor his first wife over her. So she made up the allegations of "rape and kidnapping" in order to discredit him.
Think about it: If she was really kidnapped...and really raped...why did she choose to stay with him? She had chances to run away!