<p>You should check the rules in Mass and California. The Mass rules say…</p>
<p>Nonresidents are required to file income tax returns with Massachusetts if their Massachusetts gross income (derived from sources within Massachusetts) exceeds either $8,000 or the prorated personal exemption to which they are entitled, whichever is less. Nonresidents file Massachusetts Form 1 NR/PY- Nonresident/Part-Year Resident Individual Income Tax Return.</p>
<p>The formula for the prorated income and other information for Mass non-residents can be found at <a href=“http://www.mass.gov/dor/individuals/filing-and-payment-information/guide-to-personal-income-tax/filing-requirements/who-must-file.html#Nonresident”>http://www.mass.gov/dor/individuals/filing-and-payment-information/guide-to-personal-income-tax/filing-requirements/who-must-file.html#Nonresident</a></p>
<p>Hopefully your child’s income is low enough to not require filing.</p>