> If I only convert PyFrame_New() then I would need to add it to as existing page since the patch created a new page for Frame Objects.  I think the right place would be under the current PyFrameObject in Doc/c-api/veryhigh.rst?

Not, it's a very high level API, it's a low level API which should be referenced in the concrete.rst page, as I didn in my patch.

I think it's ok to have a page with only two functions: PyFrame_New() and  PyFrame_GetLineNumber().

Move https://docs.python.org/dev/c-api/reflection.html#c.PyFrame_GetLineNumber into your new doc, but leave something like "See also :c:func:`PyFrame_GetLineNumber`." there.