What is the threshold for reporting UTMA income for my child in Virginia for state tax filing? Federal is $1300 but I'm having a hard time finding VA info. Thanks!

A dependent does not get to claim their own exemption and has special rules for the standard deduction. From the Form 760 Instructions:

Dependent on Another’s Return If you can be claimed as a dependent on the federal return of another taxpayer, your standard deduction is limited to the amount of your earned income. Enter the smaller of the amount of earned income or the standard deduction amount on Line 11.

If your child would have taxable income, file a return. If the amount is below the filing threshold, no need to file.

VA Who Must File states:

You must file an income tax return in Virginia if:

• you are a resident of Virginia, part-year resident, or a nonresident, and
• you are required to file a federal income tax return, and
• you have Virginia adjusted gross income equal to or greater than the amounts below: 

Filing Status   -   Income Threshold

Single or married filing separately  -   $11,950

Married filing jointly   -   $23,900