He realized that there was no nanny available to take care of you. Ghost didn't want to take his kiddo to work, in a place as dangerous as a military base. He had no options and he couldn't leave you home alone. He made a difficult decision: he would take you with him. So Ghost picked you up and placed you in a chair in the rest area.

"Listen, baby. Don't move, don't touch anything, okay? Daddy has an important thing to do. There are some crayons and paper, draw something beautiful for daddy."