18 year old 1099 NEC worker

Yes she has to file a tax return for it.  That is self employment income and she can deduct her expenses in addition to getting the Standard Deduction.   She gets both the Standard Deduction and her expenses.

You need to fill out schedule C for self employment business income and pay self employment tax in addition to regular income tax on it.  The SE tax is to pay Social Security and Medicare tax that wasn't taken out like on a W2.

You use your own name and ssn or business name and EIN if you have one.   You should say you use the Cash Accounting Method and all  income is at risk.  After you put in your income and expenses  if your net profit is $400 or more you will pay 15.3% for Self Employment tax in addition to your regular income tax.  The Schedule SE will be automatically filled out for it.

You can enter Self Employment Income into Online Deluxe but if you have any expenses you will have to upgrade to the Premium version.  Or use any of the Desktop installed programs.  All the Desktop programs have the same forms.  You just get more help and guidance in the higher versions.

How to enter income from Self Employment

https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/...

How to enter self employment expenses

https://ttlc.intuit.com/community/entering-importing/help/where-do-i-enter-my-self-employment-business-expenses-like-home-office-vehicle-mileage-and-supplies/00/27109

She is required to file a tax return if she had even $400 of self-employment income; she can prepare a Schedule C for business expenses.  She will pay self-employment tax for Social Security and Medicare.

If you have self-employment income for which you will pay self-employment tax for Social Security and Medicare,  you will need to use online Premium software or any version of the desktop software download so that you can prepare a Schedule C for your business expenses.

https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/26653

https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922

https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/enter-self-employment-business-expenses-like-home/L1k6HJY4A_US_en_US?uid=m6jrthmp

If you live in a state with a state income tax, you might need to make estimated payments to your state.

https://turbotax.intuit.com/tax-tips/small-business-taxes/the-home-office-deduction/L1RZyYxzv

https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/enter-schedule-c/L5Fz3j5us_US_en_US?uid=m6a6gknk

And...at age 18 she can be claimed as someone (you? parents?) else's dependent so on her own return she must say in MY INFO that she can be claimed.