Sydney mother allegedly shot in head with nailgun by stepson

A Sydney mother is in a critical condition in hospital after her stepson allegedly shot her in the head with a nailgun.

He's been charged with attempted murder and appeared in court earlier on Thursday.

Ragni Narayan, 50, was allegedly shot at by her stepson Akaash Narayan, 20, after a verbal altercation, Channel 7 reports.

A witness told Channel 7 she heard a really loud bang followed by screaming.

Police allege the apprentice builder went to his car to grab the weapon, allegedly shot at Ms Narayan, and then ran away. They say she was allegedly shot at three times.

If she survives doctors say she will be left with a serious brain injury.