I couldn't keep my mouth shut any longer!

I'm so grossed out by the mom I sit for, she thinks she is this oh phenomenal mom and she does everything right.  Well her kids come every morning filthy.  I mean filthy. I was holding the baby and her poor face was so sticky, then I looked at her kneck and she had black rings around her kneck, she isn't a fat baby so as soon as I pointed it out the mom that her kid was dirty, she was shocked and said we'll eventually she will slim down and lose her neck rolls.  The baby is in the 5 percentile for her age, she is by no means fat. She is 6 months old.  Usually this happens all the time. I finally got tired of seeing a filthy baby and I called her out on it.  Was it wrong?