I think they are a great start! You need to level things out and find a consistent white balance.
On the third one your subject should be at least a couple of feet from your backdrop. You seriously need some light into her face here.
White balance. Essentially the colour-cast imparted to the image by the difference in temperature of the light hitting the camera's sensor compared to that which the sensor expects.
For cell phone pictures these are not too bad. One thing you can do that you don't need to wait for a new camera is to find something to reflect light back into your subjects face to eliminate the shadows. A piece of white poster board will do, a long time ago I used to use one of the reflector boards that you put up on the dash of a car to cut the sun from damaging the interiror... some of those have shiny surfaces that work great for reflecting light and the way they fold makes them easy to use and self stanging depending on the set up. Get creative for reflecting light until you move up in equipment.
For a cell phone they look great ...that is why no white balance. I never liked images of people on a slant.....they would look better straight up IMHO
The baby in the leaves and the 2nd to last one of the whole family are the best. The rest have too harsh shadows and are too close to the backdrop, as has already been said