Do you mean that you should get a bigger deduction for your dependent ? The deduction is fixed per child.
The deduction will lower the amount that will be the base for your taxation.
What make you think it is not more than you thought ?
The software will calculate the deduction for the dependent that you have so there is really nothing that you can do wrong as long as you enter the data for the child correctly.
The best thing to do is to go back to the Personal Information section in TurboTax, and ensure that all of the information is entered correctly: Social Security number, name, date of birth, etc. As long as everything is correct, the software will calculate the exact amount that you should be receiving in your refund.
Since we don't have enough information or have a copy of your tax return, here is some information that could be helpful to you: