Cheese Burger/Pizza/Lasagne for 5 Month Old?

I am a US home based childcare provider, not currently on a food program, who has been working very diligently offering one food at a time (steamed/pureed) to a 5 month old infant with the parents involvement. I have been following a very detailed/signed feeding plan we worked out. Recently I began having great difficulty getting this infant to take formula from a bottle or eat from an infant spoon. Then the screaming began without symptoms of being sick.

After speaking with the parents about scheduling a doctors appointment to rule our ear infection/strep/thrush or anything I could think of, I peeked through their family photos on facebook while waiting for a return call. There were photos of this infant holding/sucking on a McDonalds cheeseburger/fries, a slice of pizza, and a couple photos of the parents hand feeding this baby lasagna and giving sips of soda by dripping it in the baby's mouth with the straw in an area restaurant. I want to scream, I have worked so hard.

How would you proceed if placed in a similar situation? Is it really any of my business? This infant is with me 5 days a week at 8.5 hours a day and has been since six weeks old.