On a side note, I'm still really pissed off at how the mom handled the whole Haley/Klaus thing. I don't know if she distanced herself from Haley out of guilt that she didn't do more or if she is just a shitty person who blamed Haley for being raped because she was 'asking for it' or something. Either way, the mom kind of pisses me off.
The way I read this is that the mother no longer trusts Haley to make proper decisions when it comes to men. Although Haley's room has been 'renovated'

, I believe the mother truly cares for Haley, but is genuinely worried about her getting into another bad situation. Given how Haley stonewalled her, I can't really blame her for thinking as she does, 'It was all my fault! I don't want to talk about it anymore!' That's how she dealt with the MC, when the subject first came up, and seems to be how Haley dealt with it with her mother too.
We really don't know how the mother found out either. Did she walk in on them? Find evidence on clothing? [Does Haley own a blue dress?] Did Haley let something slip? If we did know, would it make a difference in how we view the mother?
We also have to remember that the developers have been playing the 'Mom always loved you more' angle for comic relief at every opportunity.