No way! I just don't see that ..would be quite the plot twist if she did..nothing should surprise me in this show but still She's just saying that she did to help her mother who I don't think did it either..I believe A framed Han's mother to get to Hanna,for me it's a combination of not seeing how she could do it and not wanting it to be her that did that to Wilden.

I think Hanna was only going to confess to murder in order to save Ashley because she loves her mother.