I think being sensitive to the mistreatment of children is an awesome thing. We all must be. In my experience if you are non-threatening to the parent such as wow, the candy isle, what a cutie and start speaking with the child about anything that will get his/her attention. What also works is when a parent is getting overwhelmed to validate that and then turn your attention to the child. Baby, sing a song, do the spider ryme. Toddler, place peekaboo. Children deserve love and respect. I am glad you are getting help with this too. Child abuse leaves a horrid legacy.