It depends.
The stimulus check for dependents only applies to qualified dependents under the age of 17 as of December 31st of the year.
If your children were 17, even if they are students, you would not be entitled to a stimulus payment for them.
See the following for more information.
What does the stimulus package mean for you?
If you determine you should have received an additional $500 for each dependent, when you file your return in 2020, you will have the opportunity to report the amount of the stimulus check(s) you did receive.
If it was less than what you were entitled to, you will receive a credit on your tax return in 2020.