Last night before I forced myself to go to bed I saw a lot of comments celebrating Molly, but laced within them were comments that she really didn’t matter to Sherlock, that he had to have a last minute about face to get her help, and look at how gracious and lovely she was to help him despite that.
I don’t think that’s true at all.
I think Molly did matter to him and that she always did. But I think Sherlock was so profoundly uncomfortable with her attempts to flirt with him that he didn’t really know how to react to her in a positive manner.
Look at what happened when Sherlock met “Jim from I.T.” and dissected him in front of her, ending with, “I suggest you break it off now and save yourself the pain.” He was actually trying to be helpful. Also various people have read the way he took her apart at the Christmas party as his attempt at friendly banter, trying to make conversation with her the way she was making conversation with everyone else. He’s not exactly friendly in general with John or Lestrade (or Mrs. Hudson for that matter, how many times does he yell at her or tell her to shut up?), and yet it’s obvious they are very important to him. So if he’s mean to Molly, we just assume that she’s the one he genuinely doesn’t like?
Also note the conversation between himself and Jim on the rooftop vs. his conversation with John. Jim tells him he’s going to kill his friends, and Sherlock questions, “John?” Jim cuts back with, “Everyone!” and Sherlock questions “Mrs. Hudson? Lestrade?” Jim returns with the “Three snipers” comment, so Sherlock automatically knows that he’s left out Molly, that Molly is safe, that his plan is safe. And yet when he talks to John he tells John specifically to tell Molly, even though Molly is presumably in on the trick, so that if Jim’s followers don’t make the same mistake, Molly will be outside suspicion.
If she wasn’t important, why would he deliberately try to protect her? Why wouldn’t he just use her and go on about his business?
I think that Molly flies under Jim’s radar simply because he underestimates her. Jim and Sherlock are both so damn clever that they tend to do that sometimes.