Our adult child lives with us and has for the entire year, we do provide more than half of the financial support, but she has made over the $5,200 qualifying relative gross amount, but still under the $15,750 to even file taxes.
Does all of the criteria have to be met?
You have not mentioned the adult child's age or whether they were a full-time student. If they were NOT a student, and they were 19 or older at the end of 2025, and had over $5200 of income, they do not meet the criteria to be your dependent.
Qualifying relative
Yes, the person must meet all the criteria. They are disqualified by their income. The income limit for being disqualified as a qualifying relative dependent is different from the income threshold to file ones own return.
Your 25 year old non-student cannot be claimed as anyone else's dependent. They are too old and made too much. Even if they are under the filing requirement threshold, they can file a tax return to seek a refund of federal and/or state ta withheld from their paychecks.