That’s the way to do it and to help save butterflies.
My granddaughter was given a Butterfly Kit with 5 cocoons to watch morph into Painted Ladies. One didn’t open, while 4 did, with three being able to fly away. The fourth died because its wings were too damaged for it to fly.
We have a Buddleia Buttefly bush in our yard, plus another dozen types of flowers, roses, Rose of Sharons, Hydrangeas and 8 fantastic/nice smelling Milkweed plants for the Monards.
It’s gonna be a beautiful summer.
In the early fall, take her out to the countryside or anywhere else you may find stands of milkweeds. Search the milkweeds for monarch caterpillers then take them home and put them in a jar with the weeds to feed on. They'll soon morph into their chrysalis then hatch into the monarch....
A couple years ago I built a small butterfly cage then did the same thing and gave it to my niece's daughter.........she thought it was pretty cool.