Im 20 years old, I work, but I still live with & am supported by my mom. I did not attend school in 2022. I enrolled 1/10/23. Can she still claim me?

If you were not a full-time student in 2022, and earned more than $4400 in 2022, no one can claim you as a dependent for 2022.

For 2023, that may change.  If you are a full-time student in 2023, Mom may be able to claim you next year.

Q. Can she still claim me?

A. No, if you made more than $4400 of income in 2022.  She will, most likely, be able to claim you in 2023.

There are two types of dependents, "Qualifying Children"(QC) and Other ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, student status, a relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income Credit. They are interrelated but the rules are different for each.

The support test is different for each type. The support test, for a QC, is only that the child didn't provide more than half his own support. The support test for a Qualifying Relative is that the taxpayer provided more than half the relative's support.

You cannot be a QC because you are too old and not a student (under age 19, or under 24 if a full time student for at least 5 months of the year, or are  disabled). 

A person can still be a Qualifying relative dependent, if not a Qualifying Child, if he meets the 6 tests for claiming a dependent:

1. Closely Related OR live with the taxpayer ALL year
2. His/her gross taxable income for the year must be less than $4400 (2022).
3. The taxpayer must have provided more than 1/2 his support

In either case:

4. He must be a US citizen or resident of the US, Canada or Mexico
5. He must not file a joint return with his spouse or be claiming a dependent of his own
6. He must not be the qualifying child of another taxpayer

See full dependent rules at: https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Return/INF12139.html