DD didn't say 'Mum' until she was nearly 2. I don't know how long she was doing it, but I realised when she was about 20 months that she was referring to me by my first name. Toddlers are little smarty pants!!! Their antics are just so much fun

My DS is now 13 months and he already has 6 words, but I attribute that to DD being around and he has learned a lot from her. He is far more communicative than she was at this age . . . though DD had been walking for about 3 months by this stage and DS is not even remotely interested.

I think they are all so different and they have different strengths. I also think that birth order probably has something to do with when and how kids meet their developmental milestones.