Mrs Birtles was the mother of Sheila Birtles.
Sheila was Mr and Mrs Birtles's only child. In 1962, when the middle-aged couple retired and moved to Rawtenstall, Sheila elected to remain in Weatherfield and live with her friend Doreen Lostock at the Corner Shop flat in Coronation Street rather than go with them.
After five months, the Birtles wrote to Sheila hinting that they wanted her to join them in Rawtenstall. Mrs Birtles also turned up at the flat unnanounced to inspect the bedsit and ask her daughter in person. Sheila had just about managed to persuade her mother that she was getting along fine with Doreen when her clownish mate Jed Stone burst in, put two bottles of ale in Mrs Birtles's hands, and threw his arms around the girls, declaring that Sheila had a "smashing bit o' leg on 'er". The encounter confirmed Mrs Birtles's fears about the company Sheila was keeping, and she summoned her husband to try and change their daughter's mind. Although they were unable to talk Sheila round, they agreed to her landlady Florrie Lindley's proposal that she write to them every so often to let them know how Sheila was doing.
In January 1963, when Sheila helped Jed out at his stall on the market, they let people think that they were going out together for a laugh. Florrie, who wasn't in on the joke, sent the Birtles a letter informing them about Sheila and Jed, leading them to pay a visit to Weatherfield to properly meet Jed. Jed was highly shocked when they accosted him at his lodgings and asked for a word with their future son-in-law. It wasn't until they'd got hold of Sheila that the misunderstanding was cleared up.
Florrie maintained her correspondence with Mrs Birtles but having jumped to conclusions once, she decided not to tell her about Sheila's troubles with womaniser Neil Crossley in the summer of 1963, hoping that it would blow over. She came to regret the choice, as the fling ended with Sheila nearly attempted suicide. In order to aid her recovery, Sheila contacted her mother herself and moved to Rawtenstall straightaway, no doubt pleasing her overprotective parents.