Cops yesterday arrested the thug who killed a Queens nursing assistant while aiming for her teenage son — who wasn’t even the right target, authorities said.

Malik Wallace, 20, allegedly blasted Christina Coleman, 39, at 5:45 p.m. Saturday outside the Pomonok Houses, where she lived.

Coleman was in her Volkswagen with her son Hassan Gil, 18, when Wallace fatally shot her in the head, cops said. Gil was also hit, but he survived.

Sources said the killer was gunning for Christina’s older son, Mark Coleman, 22.

Wallace was charged with murder and assault.