Write your D'var Torah!
Tell people what your parsha is and what happens at first.
Talk about the relationship of Moses, Miriam and Aaron - they all go back a long way! To birth!
Miriam waited for Moses when he was floating down the Nile and cared for him.
Aaron was Moses' spokesperson.
Then share what we learn from the parsha.
Connect it to the other sibling rivalries, if you want to expand on the topic.
Talk about what you/we learn for our lives from the Torah portion.
These two sources show how Moses and Miriam had a special relationship. She waited for him when he was in the basket on the Nile, and they later in life led the music and singing after the Children of Israel crossed the Red Sea.
Who is God really mad at? It could be that God is upset with ALL of them - the three siblings! For fighting in the first place. The normal way we read it is that God punishes Miriam with leprosy. But, another way of looking at it is that God makes a "miracle" of sorts and whitens her hand, so that the brothers' compassion and caring is called into action.
Then Aaron and Moses pray for her! Each in their own way takes responsibility. Here Aaron and Moses are seen working together to ask God to heal their sister. Really they are all asked to their parts in getting the siblings back together, so that they can lead and the People can move forward. There needs to be not only healing but a cooling off time. The People are patient, because they know Miriam, Aaron and Moses are "working it out" with God's help.
WHERE ELSE DO WE FIND SIBLING RIVALRY IN THE TORAH?
Isaac / Ishmael
Jacob / Esau
Joseph & The Brothers...his father gave him the cloak with stripes or colors / they threw him into the pit / ...dreams...that he was better than all of them...then all the brothers got jealous and mad...sold him for slavery....went down to Egypt...but he ultimately landed in Pharoah's court!
In the end, after their father's (Jacob's) death, when they all lived in Egypt, in Goshen, the brothers worried that he would exact revenge. Instead, what does Joseph say? He forgave them and said God arranged all this!
So what does that teach us? Could be that God is more in control than we know, and when it comes to siblings - there's going to be rough spots! Hopefully not as bad as Joseph's and his brothers'.
And if we put trust in God - as Moses, Miriam and Aaron did AND as Joseph did they can accept their situations and be happier and work better together.