my 16mo dd has always been slower that average to do everything so I'm not particularly bothered that her speech is not developing. However she has mild tongue tie and had breastfeeding and weaning difficulties and now I'm just beginning to wonder if it could be affecting her speech development. She can say 'ta' and makes some babbling noises like 'mamamamamamama' and 'dadadadadadadada' and that's it. She understands everuything and shakes and nods her head and points. She's almost 17mths, when should I be worried?