I recall her saying something along the lines of 'his story sounds off, but I can't believe he would have done anything to Maleah' right at the beginning, but that seemed to fall apart pretty quickly. I don't recall her being defensive, particularly, just that statement (but I haven't been on her FB or anything, she could have been much more vocal about this and I just don't know it). I think being in denial about his involvement at first would be a fairly normal response to something like this.
I am FAR from nominating her for Mother of the Year, I want to make that clear. But this isn't some guy that she'd been dating for a few weeks, they lived together, had another child together - of course at first she would be in denial that he could have done this. To accept it would mean a) her child is likely gone forever and b) her choices played a role. I think she's coming to those realizations today.