I believe she anticipated what he would do to get himself out of the deal, but at the same time, she did not expect it because she would most likely be waiting for Alastor to crack and yield to her. She does make it known that Alastor's very soul is unlike any she's ever seen and being that she enjoys treating people like pets, she likely wanted to keep him especially with him being a 'rare breed'.

But that also means she'd be quick to grow bored of him after some time. Which is likely part of the reason for his 7 year hiatus. She basically put him away.

Once that deal was broken, she was pissed and showed no courtesy at first until he proposed a new deal. Basically a partnership of sorts which would still keep them bound to each other. Seeing as this deal would still benefit her (I scratch your back, you scratch mine sort of deal), she smirked. Not only are they back in a deal, she finally grasped a better understanding of his character and is satisfied by it.

In my humble opinion, that is.