Hi Jan and welcome to the forum.
Appends and footers are really intended for use with information that will potentially repeat for several records. If you want to use them on a one to one basis with a detail record you have to have a means of doing that within your report structure. By that I mean that your append (or footer) trap needs to 'see' a new record every time the detail record changes.
This is possible for many reports but not all so each report needs to be looked at individually.
If you could get the Notes into the detail record it may be the best solution to your problem. I assume that when you do capture them you are already using a multi-row field set to MEMO type. This sounds like it is necessary no matter what sort of template you capture in.
If the Notes section is clearly marked with some text, for example;
NOTES: Here are the notes for this patient ....
Here are the notes for this patient ....
You can make use of the Advanced Properties for the field to populate it in the table as a DETAIL field only when it exists which in my example is determined by the character string "NOTES:" appearing in the lines between the start of one detail trap record and the start of the next detail trap.
If the tag "NOTES:" always exists but sometimes has no text that will have the same effect - some records will be populated and some not.
In either case you can use the advanced field property to "Start field on .." and set a Preceding String value of "notes:" (without the quote marks) to identify the field. In the second example you would need to use the 'String anywhere on the previous line' version of the field identification feature. (That may require some care ti make sure the string is unique enough that it was not likely to exist at other points as well!)
You could use the same technique with appends and, potentially footers PROVIDING they are always 'refreshed' whenever the detail record changes. In effect the append trap would need to be the same (or more or less the same) as the detail trap so that whenever the detail trap changes the append will as well.
However if a "Notes:" string always appears for every detail record (acting like a data placeholder or tag), with or without any text following it, then it can become the trap for a footer.
The Help section for "Capturing a Multiple Line Field" covers the core functionality.
The unusual aspect described above is the technique of defining a template trap that matches the detail trap so that an Append always gets reset for every Detail template. Whether that would work is likely dependent on format of your source file.
I hope that helps.
If you can post a representative example of the report format (personal data changed or removed but accurate format and any data labels retained) to the forum we could take the development of a suitable model in a more specific direction.