The dependent can't have earned more than $4,050, but it sounds like your proposed dependent may still meet this test. However, it does sound like the dependent has taxable income, so you'll need to make sure he or she is below the limit.
Generally, social security isn't included for the dependent test, unless they're over certain thresholds/situations:
- Gross income means all income the person received in the form of money, goods, property and services, that isn’t exempt from tax. Don’t include social security benefits unless the person is married filing a separate return and lived with their spouse at any time during the tax year or if 1/2 the social security benefits plus their other gross income and tax exempt interest is more than $25,000 ($32,000 if MFJ) HERE
Also, workers comp is generally excluded for tax, but there's an exception for workers compensation offset. If the proposed dependent had additional income, the calculation would get more complicated but in this case it's fairly straightforward. Consider their taxable income to be, the amount of workers compensation by which SSA reduces their disability payments.
See pub 915 p21 https://www.irs.gov/pub/irs-pdf/p915.pdf
The relationship of the person will determine the other rules that you must pass for the dependent to qualify. If the person doesn't qualify as part of your immediate and slightly extended family, then they'll need to have lived with you all year. The software will ask about all of the applicable rules and you can see more of them here: https://ttlc.intuit.com/replies/5187060