Looking for natural consequences/positive parenting advice on the following:

My 4.5 year old daughter wakes up before my son in the mornings and ends up waking him up and causing him to cry. This is a problem because he legitimately needs this sleep. Developmentally, my daughter knows full well not to yell from room to room or leave her bedroom before her lamp turns green while her brother is sleeping (she is allowed to turn on her light and play, which she happily does most of the time). It's very stressful for me to hear the baby screaming while I'm running around trying to get everyone ready for school drop off in the morning.

I'm trying to figure out what natural consequences/positive parenting strategies can help me guide her into remembering to remain quiet during this time/motivate her to stay quiet. Developmentally, she is completely able to stay quiet and to understand why this is the rule.

Thanks!