Self employment tax for college student

[caracarn]

So this is not a FIRE tax question but lots of super smart people here so thinking I will get a faster and better answer than trying to learn this myself.

So my daughter is coming back for winter break this weekend.  I found out a few days back that rather than working her retail job, she is going to be a contractor in at my ex-wife's law office and get $10, without any withholding of any kind.  She will be working 20 hours a week and do this for six weeks, so make $1,200 by the end of January at the max.  Does she need to submit quarterly tax payments and pay self employment of 15.4 etc.?

She was making $9 or $9.50 at her retail job, so I'm beginning to think this will actually be a step back for her. 

Any help is appreciated!

[terran]

Based on Schedule SE you owe self employment tax if you make over $433 of self employed income, so it seems like she will have to pay self employment tax.

I'm not sure how her being your depended might effect this, so find that out, but ignoring that she won't how any income tax (unless she makes more than the $12k standard deduction in the year) and my back of the napkin math says she'll owe $170 in SE tax, so she shouldn't need to file estimated taxes as she'll be well under the safe harbors to avoid a penalty. See "Penalty for Underpayment of Estimated Tax" at https://www.irs.gov/businesses/small-businesses-self-employed/estimated-taxes

[MDM]

...she is going to be a contractor in at my ex-wife's law office and get $10....
She was making $9 or $9.50 at her retail job, so I'm beginning to think this will actually be a step back for her. 

For someone (such as your daughter) who won't be liable for income tax, $10/hr of self-employment earnings equates to ~$9.30/hr of W-2 wages.

Self-employment earnings minus self-employment tax = SE - SE*0.9235*(.124+.029)
W2 earnings minus FICA tax = W2 - W2*(0.062+0.0145)
SE*0.8587045 = W2 * 0.9235

SE = W2*1.0755
W2 = SE*0.9298