No. 6,300 is only for W2 income. For 1099Misc the amount is a lot less. You have to file for $400 or more. Even though she will not owe regular income tax on it (since it's less than 6,300) she owes self employment tax on it.
Self Employment tax (Scheduled SE) is automatically generated if a person has $400 or more of net profit from self-employment. You pay 15.3% SE tax on 92.35% of your Net Profit greater than $400. The 15.3% self employed SE Tax is to pay both the employer part and employee part of Social Security and Medicare. So you get social security credit for it when you retire. You do get to take off the 50% ER portion of the SE tax as an adjustment on line 27 of the 1040. The SE tax is already included in your tax due or reduced your refund. It is on the 1040 line 57. The SE tax is in addition to your regular income tax on the net profit.
