Gwen is Stacey West's mother. She is a widow in her late forties and has two children, Jason and Stacey. She is a housewife and a caring, kind woman who sometimes does a bit too much for Nessa. On the day of Nessa's wedding, Nessa told Gwen that she was like a mother to her. She's very close to Stacey as they spent many years living together. She's also close to her brother-in-law Bryn, who lives opposite.
Stacey lived with her during series 1. Nessa lived with her in series 2, when Stacey was living in Billericay. As of series 3 both Stacey and her husband Gavin live with her. Like the other Barry characters, she is very open-minded. Stacey mentions that Gwen is completely unfazed by the sound of Gavin and Stacey having sex in her house (unlike Gavin's mum Pamela, who found it extremely embarrassing).
Although thought to be a good cook she is only ever seen cooking omelettes; with the exception of Series 1 when the Shipmans come to stay and she prepares Chili Con-Carne and Cauliflower Cheese for Pam (which turned out to be just cauliflower and onion because she thought Pam might be vegan).
Her favourite song is "Islands in the Stream", which Bryn and Nessa sing for her at her birthday barndance.
- Gwen has an intense hatred for an unseen character called Jean (as do Doris and Nessa). It is not known why, however it must be for something severe in that this is out of character for Gwen.