My daughter is under 18, does she file her on taxes or do i add to mine?

[mmeicht]

She has worked part time for the last two months.

[Mike9241]

except for married couples, every taxpayer files their own return.  there is an exception for when parent(s) elect to report a child's income on their tax return but this usually results in a higher tax than if the child filed their own return (form 8814)

Use this form if you elect to report your child’s income on your
return. If you do, your child will not have to file a return. You can
make this election if your child meets all of the following conditions.
• The child was under age 19 (or under age 24 if a full-time student)
at the end of 2020. “Student” is defined below.
• The child’s only income was from interest and dividends, including
capital gain distributions and Alaska Permanent Fund dividends.
• The child’s gross income for 2020 was less than $11,000.
• The child is required to file a 2020 return.
• The child does not file a joint return for 2020.
• There were no estimated tax payments for the child for 2020
(including any overpayment of tax from his or her 2019 return
applied to 2020 estimated tax).
• There was no federal income tax withheld from the child’s income.
You must also qualify. See Parents who qualify to make the
election below.
Student. A student is a child who for some part

[AnnetteB6]

As stated in the answer provided by Mike9241, there are some instances where a parent can include a child's income on their return.  However, this only applies to certain types of 'unearned' income, not wages from part-time work.

You cannot include your daughter's wage income on your tax return.  If she has earned enough income to be required to file a return, then it must be reported on her own return.  

Take a look at the following TurboTax article for further guidance:  Do I need to file my own taxes if I'm a dependent?

@mmeicht

[Opus 17]

Very simply, a child’s income from working is never reported on a parents return, only on a return in the child’s own name. This usually does not affect your ability to claim the child as a dependent.