盐津铺子

Newborn      16 to 20 hours per day
3 weeks        16 to 18 hours per day
6 weeks        15 to 16 hours per day
4 months       9 to 12 hours plus two naps (2 to 3 hours each)
6 months       11 hours plus two naps (1 1/2 to 2 1/2 hours each)
9 months       11 to 12 hours plus two naps (1 to 2 hours each)
1 year           10 to 11 hours plus two naps (1 to 2 hours each)
18 months     13 hours plus one or two naps (1 to 2 hours each)

珠珠四个月，应该睡9+3*2=15，or 12+2*2=16, or 9+2*2=13, or 12+3*2=18。

事实上她睡11+0.75*3=13.25，the lower end。

当然忽然一天她会很困，连续睡上两个一个半到两个小时的觉。