@Ali1katt You get a tax identification number from the IRS--not from onlyfans. You can use that Tax ID instead of giving them your Social Security number.
https://www.irs.gov/individuals/international-taxpayers/taxpayer-identification-numbers-tin
You say you started this in 2020. You are self-employed. You do not file a Schedule C until you prepare a 2020 tax return in 2021. At this point you have made so little that you probably do not need to worry about paying quarterly taxes.
If you will be claimed as a dependent on your mother's tax return then when you prepare your own tax return you will need to say in My Info that you can be claimed as someone else's dependent. If you mess that up--your mother will not be able to e-file her own return if you file first. Then you will need to explain to her what you have been doing to make some extra money and why you filed a tax return.
https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922
https://ttlc.intuit.com/questions/2902389-why-am-i-paying-self-employment-tax
https://ttlc.intuit.com/questions/1901110-do-i-need-to-make-estimated-tax-payments-to-the-irs
https://www.calcxml.com/calculators/self-employment-tax-calculator (non-TT site)
https://ttlc.intuit.com/questions/1901340-where-do-i-enter-schedule-c
https://ttlc.intuit.com/questions/3398950-what-self-employed-expenses-can-i-deduct
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
