Frames (CChildFrame in this case) have no relationship with a document whatsoever; views do.
Although it is possible to create multiple frames with views that are governed by the same document there is additional work (coding) needed to maintain views/frames.
If you have two views that you need to display data from the same document I would suggest using splitter (static splitter) with two panes - either 2 rows or two columns.
Splitter will handle views' activation as well as connecting views with the same instance of document; no additional work needed.
There are only 10 types of people in the world:
Those who understand binary and those who do not.