Q. Shouldn't my standard deduction  be $5150?

A.  Yes, but not exactly. See VolvoGirl's explanation below. 

The most likely explanation is that you have entered the 1099-NEC income as "other income" (line 8 of Schedule 1}, rather than self employment income on Schedule C.   As other income, the $4800 is classified as unearned income and you only get a $1100 standard deduction.  Self employment, on the other hand, is earned income and gets you the "earned income +$350" standard deduction.

Whether TurboTax (TT) treats the income as self employment or other income, depends on you answer the follow up questions, after entering the 1099-NEC.  Be aware, there was a recent update to TT for this issue. 

The IRS considers anything on a form 1099-NEC to be self employment income. Enter the 1099 income, at Other Common income / income from a 1099-NEC . TurboTax (TT) will complete Schedule C  for you and allow you to deduct any expenses associated with this income. You'll also have to pay self employment tax (social security & Medicare) on any profits greater than $432. These types of payments are frequently done this way. Your "employer" is not the only one.

Thank you for this very detailed reply.  You thoroughly answered my question.

Thank you for this detailed response.

This response is fantastic. So now, how does the standard deduction apply to unemployment income? It seems that Turbo tax is putting unemployment income as "other income." I have approx 16K unearned (unemployment - covid) and only 8K earned, my standard deduction is limited to 8K. I get $10,200 as an exemption on the federal side against the 16K but I am left with 6K that I have to pay 28% on (my parent's tax rate)  My bill on approx. 6K taxable income is $1229. Is this right? Seems crazy.

Q.  My bill on approx. 6K taxable income is $1229. Is this right? 

A. Yes.  The $6K unemployment is "unearned income" and, as such,  subject to the "Kiddie tax"  (being taxed at the parent's marginal rate).

The kiddie tax was implemented to discourage parents from shifting investment money to kids' to avoid high tax rates.  But, the law was written for "unearned" income, not just investment income.  Whether it's fair that unemployment compensation should be  included, is a different question, but it is correct that it is taxed that way.