I remember reading some interview with Sarah Palin a while back, in which she was talking about her son, Trig. At the time, Trig was approaching his second birthday, I think. In the interview SP said Trig was not yet talking, and that she longed to hear him say "mama." I remember reading that and thinking, although I understand that longing, I found that I didn't feel that with Finn. The attachment between Finn and me is undeniably there, whether he says "mama" or not; there is no question that he knows I'm his mama and that I adore him, and that's good enough for me. So it really hasn't been a big deal to me that he hasn't said "mama."
Finn actually started babbling "mamamamama" when he was around seven months old. It was clear that he had the ability to make those sounds, but as far as I could tell, that's all it was - babbling. It wasn't a specific, purposeful attempt on his part to name me or address me. And after a while, he stopped babbling "mamamamamama" and moved on to other sounds.
A little while ago this morning, Finn was playing on the floor next to me as I folded laundry. Suddenly he stopped what he was doing, looked up at me, right into my eyes, and said "Mama." He had a big grin on his face, and then he started clapping for himself. It was a first: he was actually purposefully saying "mama" to me. And it was the sweetest sound in the world.