This is my daughter. I used to capture families and had plenty of experience. I loved capturing natural expressions and using significant and meaningful props (often belonging to the parents) to assist in telling a story. My daughter (Abby) would occasionally pull a funny pouting face. I worked out a prompt where she would respond by pulling the pouting face. Add in the lipstick and telling her to put it on her face and voila! I used to consider portrait shoots as a hypothesis. You put the elements into the shoot, but you should never force the finished image like you may in other types of photography. Just wait to see what happens and sometimes give a little direction. Children are honest and have no filters. Let children be children and capture that honesty!