Growth Development

I'm very concern about my girls growth development. Jie Jie is already 3 yrs plus, but her weight is only 11.6kg as measure by this morning. About Mei Mei, first 2 -3 mths, she's progressing well, but I observed that the weight is slowing down recently, I'm so worry, as she's taking 6 times milk per day, each feed is 4oz.. is she taking not enough milk?

Kait Yee:
Weight record:
02 June 08 - 2.4kg delivered 3 weeks earlier than expected date, new born weight
09 June 08 - 2.3kg weight dropped 1g
13 June 08 - 2.45kg
17 June 08 - 2.55kg
23 June 08 - 2.75kg
03 July 08 - 3.2kg
02 Aug 08 - 4.3kg
20 Sep 08 - 5.2kg
08 Nov 08 - 5.4kg (why 1.5 mths only gain 2g, is the weighing scale not accurate??)

Height record:
02 June 08 - 47cm
03 July 08 - 48cm
02 Aug 08 - 51cm
20 Sep 08 - 56cm