There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative"(QR) 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.
Since student #1 turned 24 before 12-31-2020; he no longer qualifies as a QC. There is a $4300 income limit for a QR. So, his $12k income prevents him from being a dependent for 2020. The good news is, he gets the $1800 recovery rebate credit (stimulus) when he files his 2020 return.
Student #2 is still your dependent, but that has nothing to do with recovery rebate. There is no stimulus payment for children over 16 (there is in the current proposal but that's not part of your 2020 tax filing)
The stimulus question comes up in the review section of TurboTax. You will be asked how much of the first $1200 (each) you got, then the 2nd $600. Whatever you didn't get will be added to your refund.
Q. Should i work independently with a tax preparer instead of TurboTax this year?
A. Nothing you described would warrant that.
