Hello Faith!
Regarding reading the opening and closing words, an example is to begin the recording with "Chapter 4, part 1, of Moravians in Jamaica ..." and end with "End of Chapter 4, part 1". And accordingly for "Chapter 4, part 2". Or anything else that you prefer, that would convey this meaning of chapter continuity, like the example you gave.
Regarding filenames, keep giving unique filenames like you have been doing, and at cataloguing time, they will be renamed to follow the section numbers. But as we don't know if your sister needs to split her chapters too, we can't know the accurate section numbers now. As long as each file has a unique filename and the correct spot in the Magic Window, I can settle the filenames at the end.
Both you and I can add extra sections in the Magic Window so let me know if you'd like help with that. There's an "Add new section" button when you're logged in the Magic Window. You'll be given the option of filing in Section title, etc., but you can also click "Add" without filling them in. The new section will appear at the bottom of the table and you can click on it to drag and drop it where you want it, e.g. between sections 4 and 5. I hope this makes sense, or you can refer to the Magic Window guide for more details:
https://wiki.librivox.org/index.php?title=Soloists:_How_to_update_the_Magic_Window#What_if_I_need_to_change_the_number_of_rows_in_the_table?
