Ferreira, mother of Leavitt's brother's son, was arrested in Revere, Massachusetts, accused of overstaying a tourist visa since 1999 and battery, and is now held in Louisiana.
Her sibling launched a GoFundMe campaign for legal fees, stating Ferreira came to the US as a child and maintained DACA status, highlighting her 11-year-old son's distress.
Karoline Leavitt, a staunch defender of Donald Trump's immigration record, has not publicly commented on her relative's arrest.
The detention occurs amidst a reported decline in public approval for Donald Trump's hardline immigration crackdown.