It depends. Does she no longer claim you as a dependent on her return? If not, then your mom can enter 100% or 75% and you can enter 0% or 25%. Basically, if she thought she would claim you as a dependent for 2024, then you can enter any amount for the allocation that you both agree on as long as it totals 100%.
If your mom still claims you as a dependent on her return, you would not enter the 1095-A on your return. You would just need to be sure to check the box that says someone else can claim me as a dependent on their return.