Check the background.
What’s in the background? Is it distracting? The washing on the line or a bright red car won’t look so good. Maybe move around yourself to get a plainer background. With a baby, perhaps put the baby on a sofa to get a plainer background.
Try turning the camera round so that you take an upright, vertical photo. This way up fits the shape of people better, so there’s less likely to be heads or feet cut off. If it feels odd to hold the camera like this, practise so that it feels more natural. Its also important to hold the camera steady, since if the camera jolts slightly when you take the picture, you’ll get a blurred photo. Keeping you arms in at the side of your body helps.
Try off-centre composition, and children not looking at the camera
The usual place to put your child is slap bang in the middle of the image. That’s OK, but you’ll get more interesting results if sometimes you put them to one side. A typical composition might have the child looking not at the camera, but away to one side, towards the side of the image where there is now all that space.
I hope some of this helps improve your children’s photography – more in
Better child photography – part 3.