My feelings on the question she was asked and her potential answer.
Bruce finally asked Selina to marry him. Do I think they will tie the knot? I have my doubts. She'll either say no due to not wanting to be tied down or the engagement/marriage won't last long. I have little faith that it will be more than that. This proposal happens some time after Bruce met Flashpoint Thomas Wayne who told him to stop being Batman and be happy. (Well more specifically to be a better father to Damian.) I'm not so sure that he'll stop being Batman since he's wearing the costume minus the cowl when he's proposing.
If Selina says no then there's really no change in the status quo.
If she says yes and DC decides to go through with it there's still a lot of things to go through. The bat family it's self particularly the Robins don't feel like a family at the moment. Tim Drake is still missing and presumed dead. Dick Grayson's relationship with Tim was pretty much nonexistent since New 52 started. No one (except Lobdell) seems sure how Jason Todd and Dick relate to each other. Damian gets along with Dick and no one else. If the engagement became an event this would be an excellent time to strength these relationships with each other and Selina/Bruce.
Damian probably wouldn't be thrilled with Selina being his stepmom. The friction would be present and this would likely led to conflict with Talia too. Selina is pretty tough though and her love for animals might win her some points with him.
Tim and Dick were usually okay with her. I'd think Jason should be alright with her given his background. Pre-Crisis Jason didn't like her but then again he had a mother figure he wanted with Bruce.
Until something big comes out of this I'm sorry to say I'm not too excited.