Lillian Smith was bookie Dave Smith's wife. A well dressed, well spoken women, Lillian was attracted to men who had excitement about them. She and Dave were courting as far back as the Second World War, and Lillian later kept Dave's war letters. By 1969 they were separated and living at opposite ends of the country - Lillian in London and Dave (usually) in Weatherfield, with Lillian living off payments from Dave. She had tried to live in the North with him for a while but after only a few months declared that it wasn't to her liking.
Dave wasn't one to abstain and had been pursuing Elsie Tanner for several years, and Lillian eventually found out and phoned Elsie to warn her that Dave was married. Elsie was shocked as she didn't know. Lillian quickly followed up her phone call with an appearance in Weatherfield to tell Dave she wanted a divorce on terms of adultery, citing Elsie. Dave contested the divorce but Lillian was determined to win and asked the neighbours about Elsie. She was disappointed to find that most of the neighbours weren't willing to get involved, even the local gossip Hilda Ogden. Lillian accepted an offer from Dave for more money each week, in exchange for no divorce.
By August, Lillian had met Leo Slater, a Londoner even more crooked than Dave. Leo had a shady past but Lillian accepted it when he told her. They agreed to marry and Lillian travelled up to Weatherfield ahead of Leo to tell Dave her plans. Dave enjoyed reminiscing with Lillian but was wary of Leo and spent time trying to suss him out. When he found out about Leo's past, Dave told Lillian and was shocked that she already knew. Lillian also enjoyed intimidating Elsie by showing up at Alice Pickins's hen night, although Elsie was no longer seeing Dave. Dave decided to grant Lillian a divorce, and Lillian and Leo left for London.