Shelby is very adaptable to change. she is on a regular sleeping, eating, and waking schedule. thomas and chess would describe shelby as being a (n)

The correct answer is easy child.

No child is undemanding - parents have to be around their baby at all times, caring for it, and tending to its every need. But this child can easily adapt to anything, which is why she doesn't really take up a lot of her parents' time, and doesn't cause problems.