The first thing to note is that FIDE make the rating calculations not Chess Stack Exchange. We can try and explain their calculations but we cannot change them or influence them in any way.
Here is the page on the FIDE website where your daughter's August 2023 calculations are made. As you correctly point out a K factor of 24 was used instead of 40. Three tournaments were rated in which she played a total of 29 games.
FIDE Rating Regulations effective from 1 January 2022 is the document on the FIDE site which explains how the rating calculations are made. Regarding the K factor it says:
8.3.3 K is the development coefficient.
K = 40 for a player new to the rating list until they have completed events with at least 30 games.
K = 20 as long as a player's rating remains under 2400.
K = 10 once a player's published rating has reached 2400 and remains at that level subsequently, even if the rating drops below 2400.
K = 40 for all players until the end of the year of their 18th birthday, as long as their rating remains under 2300.
If the number of games (n) for a player on any list for a rating period multiplied by K (as defined above) exceeds 700, then K shall be the largest whole number such that K x n does not exceed 700.
I have added emphasis to the important part of the rules above.
Your daughter has 29 games in the rating period. 29x40=1160, much bigger than 700. The largest whole number such that K x n does not exceed 700 is 24 when n=29. 24x29=696. That's why a K factor of 24 was used.
