I am worrying about my baby girl's weight.. My baby's Birth weight 3.1 Month 1 = 4 kg Month 2 = 5 .1kg Month 3 = 6.2 kg. Month 4 = 6.8kg Month 5 = 6.9kg month 6 = 7.2kg now she is 13 months old..her weight is 7.7kg. and height is 82cm . she is active and fine.. she started crawling at 6 months..and standing with support in 6 and half months.at one year she walks independently... but her weight is not tripled.