According to British newspaper the News of the World, Charlotte and her party turned up at a restaurant in Cardiff's Chip Alley on Wednesday at 11pm.
After spending £50 on house wine and a bowl of chips, Church then allegedly shouted at her mum Maria.
A diner at the restaurant said: 'The women were all legless. Charlotte was in the worst shape - she was absolutely hammered.'
The 25-year-old, who split from Gavin Henson last year, was said to be angry after her mother suggested she couldn't keep a man.
When the pair went outside, Charlotte said: 'What have you achieved? You've achieved being a Welsh mother and a wife. Well done.'