The Corrie Wiki page appears to be explaining how Debbie is Carl's mum, and how Bill and Elaine (Debbie and Kevin's stepmum) came to have Carl. But I do wonder if all this information was available on here before this week. 🤔
https://coronation-street-past-and-present.fandom.com/wiki/Elaine_Webster
From the page...
Elaine Prior was born around 1946 to Walter and Millie Prior, nee Sugden. Her mother's brother is Percy Sugden, who moved to Coronation Street in 1983.
1984-1985
Elaine came to Coronation Street to visit her uncle Percy Sugden in November 1984. She began going out with builder Bill Webster, which disappointed Percy as he hoped that she would get with businessman Mike Baldwin and not a 'mere builder.'
Elaine and Bill spent some time in London together and later decided to get married. Percy gave his blessing for the wedding after being convinced by Bill. Bill and Elaine married in January 1985, and moved to Southampton with Bill's daughter Debbie coming with them, although his son Kevin decided to remain behind in Weatherfield.
After 1985
By May 1986, Debbie was pregnant after a dalliance with an unknown man, but to cover up an illegitimate teenage pregnancy, when they kept in touch with Kevin back in Weatherfield, they let him think it was Elaine who was pregnant.
Debbie gave birth to her son Carl. Carl's grandad Bill and step gran Elaine bought him up as their son. Carl and Kevin were unaware of Carl's true parentage. The family later settled in Germany. Debbie left the household and began making a good living for herself.
In 1994, Elaine had an affair behind Bill's back - with Bill's boss. Bill thumped his boss and got the sack. They separated and he returned to the United Kingdom and to his family on Coronation Street. Their son Carl continued to live with her. The pair divorced.
In December 1996, Elaine and Carl were visiting Bristol and Bill went to visit them in order to see Carl again. Elaine and Carl didn't have a good relationship and she viewed him as a waste of space growing up. It is suspected she only kept him around to punish Bill.
By 2016, Elaine was back living in the United Kingdom and once again living in Southampton. Carl continued to live in Germany.
Elaine Webster is seen in a photo Debbie Webster has in 2025 from 41 years earlier in 1984.
In 2025, Elaine's son Carl visited Weatherfield and moved there, and soon started getting into an affair with his sister in law Abi Webster.
In September 2025, Debbie looked at a photo of Elaine on her wedding day to Bill in January 1985.
On 10th December 2025, Elaine left a voice message for Debbie asking her to
phone her back.
Later in December 2025, Carl said Elaine has died of cancer.