Karen Lomax was the wife of Colin Lomax and mother of Jason. In September 1972, the Lomaxes visited Weatherfield from West Hartlepool to visit Colin's grandmother Ena Sharples, who he hadn't seen in years. Ena in turn had no idea that Colin had married or that she was a great-grandmother. Calling at Ena's Community Centre accommodation, they were informed by Lucille Hewitt that Ena was away on a Street outing to the Preston Guild and wouldn't be back until late in the evening. With nowhere else to go, they spent the remainder of the evening nursing drinks in the Rovers Return, although as Annie Walker refused to have a baby on licensed premises, Karen volunteered to leave Jason in his pram outside so that she and Colin could stay and wait for Ena.
They had only been there a short time when Karen went out to check on Jason and discovered that pram and baby were gone. The police were called immediately and the Street residents who weren't at the Preston Guild rallied round to help the police with their enquiries while Colin and Karen were looked after by Annie and a policewoman in the Rovers back room. When questioned by Det. Insp. Patterson, Colin was near-catatonic and Karen hysterical. The kidnapping sparked a large-scale search by the police and the army, but fortunately the baby was found after two days by Betty Turpin and Emily Bishop, his pram abandoned on waste ground with Jason unharmed inside. Ena returned in the midst of the investigation having been summoned home from the Preston Guild. The kidnapper wasn't identified until January 1973 when Christine Peters's suspicious behaviour caused Emily Bishop to investigate and discover that she snatched Jason as she had lost her own baby and was suffering mentally from the loss.
Ena spent Christmas with the Lomaxes in Hartlepool in 1972 and also visited them in February 1978. When Ena returned to the Street the following month, she revealed to her friends that Colin and Karen had asked her to stay permanently but that she had graciously turned down the offer.