Molly still wears her heart on her cold sleeve for Harry, but after her experience with Carlos has resigned herself to that can never be. That is the feeling I got as per their conversation in the limo after Mab sprung the nuptial news on Harry. I also think she knew this was in the wind before hand, that would account for the literally frosty looks and if looks could kill exchange that she had with Lara when she and Harry returned to shore after defeating the kracken. Given that the Files is Harry's memoirs looking back, it is significant I think that he makes a point that that exchange between them went over his head and he missed it. Definite dirty,icy water ahead....
To put it mildly, Molly doesn't approve. Here is a wild thought, maybe Mab wanted Harry to kill Molly if she fell in battle, not because she is worried about how Molly would rule, but because that would blow up her wedding plans for Harry and Lara.