You didnít say much on what all approaches you have already tried. There are many things you can try here though. Like you can try setting up an event based communication amongst all the child forms.
Maintaining a collection of the children classes in the parent form, as you mentioned is another approach you can try.
And off course instead of asking ďif Iím asking it correctly", if you just explain it how you yourself would like such a problem to be explained to you, it will help people over here immensely in understanding your queries better.
For an instance at times a few pieces of code say a lot more than the tomes that people write explaining and documenting them.
Do write back, if thereís any thing else you wanna discuss.