Probably the best way to get pictures of children is to NOT pose them. That invariably looks fake.
Just get at their level and keep taking pictures until they get tired of looking at you.
Then you'll catch them at their normal activities which makes for much better pictures.
Learn to focus on their eyes, shoot at f stops at the more open end of your lens (smaller numbers), that will allow faster shutter speeds. Use higher iso so that shutter speeds can be higher.
Review the pictures and find what is working.
Don't use on-camera flash (I would say don't use flash but to each his own.)
Photography is a craft and an art just like painting or pottery or sculpture.
Even though modern cameras make it easier you have to get some understanding of what you are doing in order to concentrate on making it look good.
I've been in healthcare for a long time and it is my impression that dedicated nurses are the smartest people in the hospital and so I have confidence that you can do it. It is just a question of application. (and, if you have it, some money)
I am decidedly not a child photographer but by working at it, even I can produce the occasional decent child picture. (
example 1 ,
example 2)