I feel very sad for your chameleons. mostly because if you googled any chameleon website they all clearly state that veiled chameleons, let alone any species of chemeleon, should NEVER be housed together in the same enclosure. They should never even see eachother it can be so stressfull.
I have a male and two female veiled chameleons in totally seperate rooms of my house, just so they can't see eachother.
egg laying is very taxing on a fragile chameleons body. female chameleons should not be bred before the age of 1 year. if they are younger, their bodies aren't done growing and all their nourishment goes to egg production and they become malnourised.
over time stress can kill chameleons. stress of being in the presence of a male, plus the stress of egglayinng on top of probably not the best husbandry methods killed your chameleons.
i am a teacher and here is a good way to interact with your children and learn new facts. show her how to google "veiled chameleons" online. browse all the diffrenet web pages out there. go to the libary with her and check out books on chameleons. have your daughter compile a list of facts about chameleons and write it into a little paper, care sheet or a home-make book on chameleons, example : "facts on chameleons" (depending on her age). you will learn how to properly care for them, she will learn their care too, she will also enchance her research, study, reading and writing skills. also, your future pets will gain because they will recieve the proper care. everyone wins!!! This works great with all age groups of children. I suggest everyone doing this with your children BEFORE any new pet is brought into the home. That way everyone is has researched and prepared for them.