I sit my baby up in his stroller now and he is just over 3mths. He gets frustrated with laying down too sometimes so when he starts getting antsy, I sit him up. he is quite good at sitting upright though. Does the P&T have adjustable seats where you can have them propped up just a little bit? My big pram has three sitting adjustments which is good for when they don't quite have the head control to sit fully upright.