Indesign Table of Content Parent page

Yeh TOC won't pick up parent pages 

Couple of ways

Use a hidden TOC style marker in the document

Instead of relying on the Parent page text:

Put the section/chapter title once in the document text flow (on the first page of the section).

Apply a dedicated paragraph style (e.g. TOC_Section_Title).

In Layout > Table of Contents, include that style.

On the Parent page, continue to use:

Type > Insert Special Character > Markers > Section Marker

Hide the “real” section title if you don’t want it visible:

Set it to 0 pt

Or put it on a non-printing layer

Alternative: Use running headers tied to real text

If your “Section Text” is effectively a running header

Put the section title in the document once

Use Text Variables > Running Header (Paragraph Style)

Place that variable on the Parent page

This still requires the source text to live on a document page, but you only enter it once per section.

Let us know if that works for you.