I don't think Amy's done anything wrong either. I genuinely believe the girls like Lucie and just want to see her more.
Keep in mind how Joe acted in that first week. Amy called it straight away and thought his behaviour was manipulative (which almost everyone here agreed with). Now she's spending lots of time with Joe. She just wanted to make sure she was ok. And, tbf, Lucie was happy to get all her advice and support when she needed it then sacked her off pretty quickly.