Secondly, they aren't white.. While some double merle dogs are almost pure white, they can go the complete range all the way up to a dog that you would think is a just a normal merle (most fall somewhere in the middle).
In between five and six months, your baby usually starts to sit up with your help, holding his head in an upright position, keeping the back straight. He may even be able to sit for a second or so without taking any assistance from you, before toppling down after a while [1] .
Nearly all babies can sit on their own by the time they are nine months old (NHS 2013, Sheridan 2008) . While you can prop your baby in a sitting position almost from day one, sitting independently doesn't begin until your baby has head control. Three months to four months.