Common-law Status kicking in end of 2025 tax year - Implications on Gvmt Benefits?

Hi, my partner and I moved in together December 2024, and became common-law for tax purposes as of December 2025. How does our common-law status affect the tax year of 2025 if we were only common law for only around a month of the year?

We mainly want to know how the status change affects the Canada child benefits or GST benefits throughout 2025, since my partner has a son that lives with us, and if it will result in having to pay back much of it even though we only became common-law at the end of the tax year.

My income is much higher than hers and will likely eliminate any benefits for the following years.

any info/advice would be appreciated. Thanks!