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] .
Susie Alessi's son was also around 6 months when he began to sit up by himself. We did tummy time and 'baby pushups' where I would lay him across my legs and make him lift up or push up off of the floor with his hands, she says. That kind of practice is very important in helping babies reach milestones like sitting.