Babysitting a breastfed baby.

I nanny alot, one 5 month old I have is a breastfed baby, which I think is great. However the mother won't pump so I have to take him to her every 2 hours 😕 and he is super dependent and loving with her. Lately he has been needing her in his eyesight, or he cries...actually screams. It doesn't matter what I do to help. She is aware of this. Is it worth me doing this? Should he just be with her? The screaming is unbelievable. Is there something I can do?