If your daughter was an employee, she should be issued a W-2 for her earnings. However, if she only worked 2 days at the end of December, she wouldn't have to report the income in 2023 if the pay period didn't end until January and she gets paid in January for the 2 days worked in December.She would report the income on a 2024 return if she is paid in 2024.
A cash basis taxpayer reports income when it is actually received, and reports expenses when they are paid. The majority of people who file individual income tax returns are cash basis taxpayers.
See here for another discussion of this issue.