''I believe I read somewhere that part time students cannot be claimed as a dependent"
Not exactly.
There are two types of dependents, "Qualifying Children"(QC) and standard ("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, full time student status, a relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income Credit.
Being a part time student, over age 18, means you cannot be claimed under the QC rules, where there is no income test. If your income was less than $4200, you may (probably) still be claimed under the Qualifying Relative rules.
See full rules at: https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Ret...
