A mother-of-two was left distraught after a diner in a Fremantle pizzeria, who declared restaurants should never seat people eating alone within five metres of children, abused her because her young daughters were "a little noisy".

Caroline, who didn't want her last name published, was having lunch at Portorosa Cafe in Market Street on Thursday when a woman in her 40s staring hurling insults at her.

The aggressive diner believes people eating alone should never be seated next to children. Credit:iStock

"My daughter, who is one, just found her voice so she was squealing," Caroline said.

"She started abusing me saying 'you can't control your kids, people like you shouldn't bring kids to a place like this'.