When to confront someone about a behavior ?


My child is looked after in a daycare managed by three nannies. I get along well with the nanny who takes care of my son. However, when I accompany her in the morning, I notice that another nanny is very rude to the children she is babysitting. She yells at them impatiently, and when they cry, she yells at them again so that they stop crying. I feel really uncomfortable every morning when I see this behavior.

Circumstance : I arrive in the morning with my child to the daycare. While I’m speaking with his nanny, I see the other nanny yelling at the children that she takes care of.
Thoughts : Poor children, this is psychologically violent for them. She needs to know that this is not acceptable. It is also my responsibility to do something.
Feeling : awful, outraged
Action : Nothing for now. During the day I remember the children and feel awful.
Result : Nothing changes.

Intentional model :
Circumstance : the same
Thoughts : I accept my feelings. And at the same time, I should do my part and communicate my opinion.
Feeling : sad and empowered
Action : Speak first to the nanny who takes care of my child to know her opinion about her colleague behavior and the situation
Result : probably some change

Any help please with the intentional model ?
I’m probably trying to change the nanny’s behavior in order to change my feelings, but I do think that I have a responsibility to react here…
Thank you !