Do kids award seats cost less points?

Hi, we’re a family of 5 taking a year off to France, departing from Sydney before Christmas 2023.
As my 11yo is finishing primary school I decided to go with her in Dec and thus purchased a one way ticket (non-oneworld)
And to save cost I booked my husband and 2 younger kids on classic rewards one way outbound and wait til before they depart to book the return ticket, (also to be eligible for the complimentary travel insurance) which im now about to do.

Now for the return, we’re hoping to go altogether meaning booking 5 one-way classic rewards. My eldest wouldve turned 12 by then.

Qantas website cites

“If your child turns 12, or your infant turns 2, after travel has commenced, Qantas will allow you to use the ticket at the reduced fare within its validity.”

Since i book 2 one way tickets i wonder which part is our commencement of travel?
In this case do i need to book an adult ticket for her?

Your help and clarification would be immensely appreciated, TIA.

I suspect that quote is for paid fare. Any discount does not apply on award seats. 0-2 years old you travel “free” as lap infants. Beyond that, a 3 year old passenger and a 30 year old passenger pays the same amount of points for a seat.