[4] In November 2012, music manager David Cooper began a three-month process of auditions for a new girl group to be signed to RCA Records UK.

Plummer, as well as Amira McCarthy, were separately scouted while shopping in London, while Shereen Cutkelvin and Asami Zdrenka were found via their solo YouTube videos.

In February 2013, it was announced that Plummer, alongside Cutkelvin, McCarthy, and Zdrenka made the line-up of new British girl group Neon Jungle.

[14][15] In November 2015, it was announced that Plummer has joined the cast of John Cameron Mitchell's directed romantic-comedy film How to Talk to Girls at Parties opposite Ruth Wilson, Nicole Kidman, Elle Fanning and Matt Lucas.

[17][18] In March 2019, Plummer joined the BBC soap opera EastEnders, portraying the role of Chantelle Atkins.

In September 2020, it was announced that as part of the storyline, Gray would murder Chantelle, in order to reflect the mortality rates displayed in abusive relationships and highlight the impact of the COVID-19 pandemic on domestic violence.