Please I need some advice on a baby please. At wits end

I work in daycare infant room. I have worked in childcare for many years and have a lot of experience with babies. I know all babes are different and I’ve had great babies and some that were a little more challenging. I always make it work and can usually figure out the kids pretty quickly. Except for now.

I have an 8 month old girl I take care of and she’s been in my class for 3 months now. All this girl does is scream. Bloody murder. All day long unless I’m holding her. I will be sitting on the floor with her in her face and she’ll still scream until I hold her. I don’t have time to carry her all day. I have 4 other babies to tend to and feed and change and give attention to. If I hold another baby she melts down. If I feed another baby she melts down. Basically if she’s not in my arms she melts down. This baby is mobile (crawling) and sits up on her own. I am at my wits end. I have no help in here so I can’t walk away and her parents are no help. Mom carries her all day at home and has admitted to it. When I give her my concerns she brushes it off and laughs. I go home with migraines and stress every day. I try to let her cry it out on the floor or in a play seat but she screams so loud she turns blue. But the second I pick her up she shuts it off. Please can anyone give me advice. I have no idea what to do. I’m at the point where I’m about to cry in the middle of work I’m so stressed.