Her biggest role came through her casting as receptionist Lizzie Hopkirk (Kennoway) in ITV UK TV series The Royal. The 1960s-set hospital drama was a spin-off from Heartbeat and soon gathered popularity on its own account. Hardwick's portrayal of the ditzy Lizzie (often referred to as "Dizzy Lizzie") was a firm favourite amongst viewers. Lizzie delivered some very funny lines, including "A woman needs a fish like a man needs a bicycle". She was known for getting well-known phrases mixed up, malapropisms and general comedic lines. However Hardwick also demonstrated Lizzie's more serious side when she had to deal with her husband leaving her in the episode "For better for worse".
She has taken notable roles in Heartbeat and Coronation Street. Michelle has appeared in three different episodes of the ITV UK TV series Heartbeat (1995 as Sandra in "Toss up"; 2002 as Lesley Sutton in "Coming of Age", which featured the death of character PC Tom Nicholson, played by Ryan Early; and finally in 2003 as Lizzie Hopkirk in "Out of the Blue"). Hardwick appeared in Coronation Street in 1997 as Sheila Dixon and in 1998 as Naomi Russell.
In October 2012, it was announced that Hardwick had landed a role in ITV soap Emmerdale. She was to play Rhona's wild friend from college Vanessa Woodfield, who had been tipped to shake up life at the vets' surgery. Vanessa was billed as a "self-assured party girl" who would be "like a breath of fresh air" when she arrived at the vets' practice. While Vanessa is always up for a laugh, she is also plain-speaking and instantly clashes with Rhona's husband Paddy. Hardwick commented: "As a local girl and a fan of the show, Emmerdale is my dream job. After only two days, I am starting to feel at home already and Vanessa is such a fun character. I can't wait to see what's in store for her." Vanessa will appear on screens from December. Hardwick and Vanessa have proved popular with audiences, and with one of Vanessa's storylines, the character has helped people to come out as gay.
Hardwick is openly lesbian. In July 2013, she spoke publicly about her sexuality for the first time, confirming that she was in a long term relationship with music Teacher Rosie Nicholl. The couple became engaged on 31 December 2013, and married on 4 April 2015. In 2017, Hardwick announced they were divorcing.
