Ermine redirects here. For other uses, see Ermine (disambiguation). The stoat (Mustela erminea), also known as the short-tailed weasel, is a mammal of the genus Mustela of the family Mustelidae native to Eurasia and North America, distinguished from the least weasel by its larger size and longer tail with a prominent black tip.
Although there is a wide range of ages at which babies stop burping, if your daughter is now 4 months old, and does fine without burping, then you likely can simply stop trying to burp her. It may be that she is just not swallowing much air as she eats anymore.
Babies can be sitting from 6 months, Crawling from 4 months and walking from about 7 months. Your baby will do it when he /she is interested enough. Don't worry about what other babies are doing. The  normal  range stretches a long way.