I've spent months (seven months actually) trying to get a reaction from Madame. The first couple of months I got nothing. Then I was able to get a smile and eventually laughter, which is very satisfying (and addictive on my part). She recognizes people, songs we sing to her, favorite toys; but the most of a reaction we can get is some squeals of happiness and some kicking. No amount of waving, clapping or "Give me a smooch" gets the appropriate, reciprocated response.
And then yesterday it finally happened. We were hanging out playing, and I clapped to her. She looked at me, took a second, and did it back. Needing to make sure it wasn't a fluke, we did it a bunch of times the rest of the day and let me tell you, it was pretty awesome. When she speaks her first word I'm probably going to completely freak out.