C.N.
Dear S.,
Well, for one thing I am the grgrandmother to a 4 year old and a 2 year old and your sister's senario sounds familiar. Your sister has got to harden her heart and let the 4 year old vomit! Then wash her face with cool water, put her in a comfortable place, and let her rest - tv or whatever.No scolding, just do this with love and no talking. maybe hum so she won't seem to be angry. That tv isn't such a bad thing as some people suggest. It redirects the child's thinking and gives them a bit of peace and chance to let their body rest.
She also needs to be stopped immediately when she starts being bossy and screaming at anyone, especially mom ! Put her in her room, and have a gate on the door so that she won't be so isolated. Let her scream and throw and whatever, but needs to stay there until she is calm. It might take a while, but it is worth the horror of having to do that to your child.
The two year old deserves to play in peace and be a person too. Have the 4 year old 'read' or teach the 2 year old something or do something for him or her when she is calm and loving. Just do it. It is worth the peace that you will gain.
I am not only telling you to do this, I have done it, several times, after all I am almost 76 years old and have helped many young ones get through the first 5 years. No, I did not do day care. I worked with children that were very close to my heart. As I am sure day care children are to their caregivers, just wanted to show you how bonded I was to my little people.
Sincerely, C. N.