Assuming that she is a dependent and the income received was Not from self-employment but was from unearned income, she would Not be required to file a 2018 tax return since her unearned income was $810.
IRS Publication 501, Dependents, Standard Deduction, and Filing Information page 4 - https://www.irs.gov/pub/irs-prior/p501--2018.pdf#page=4
Single dependents—Were you either age 65 or older or blind?
No. You must file a return if any of the following apply.
1. Your unearned income was more than $1,050.
2. Your earned income was more than $12,000.
3. Your gross income was more than the larger of—
a. $1,050, or
b. Your earned income (up to $11,650) plus $350.
