Prior to the events of Kingsman: The Golden Circle, she and Charlie split up.
Kingsman: The Golden Circle
Meeting Eggsy and Tracking
After Agent Whiskey's failed attempt, Eggsy succeeded to hook-up with Clara, under the false name 'River'.
Clara and Eggsy then enter her tent, where Eggsy goes to the lavatory. In there, he calls Princess Tilde and asks for her permission to allow him to place the tracker in her, which places strain on their relationship. In order to stop the Golden Circle, Eggsy quickly places the tracker and then leaves.
At the concert she eventually takes some type of drug, and develops 'blue rashes'. She then calls Charlie asking him for an antidote, to which he instructs her to go to Italy. The call was intercepted by Merlin thus revealing the location of the antidote.
Italy and Death
She then travelled to the Antidote Factory in Italy and drank the antidote, but was surprised when 'River' (aka Eggsy) arrived. Charlie then pursued Eggsy after he stole a vial of the remedy.
As Charlie leaves the factory in a helicopter, she begs him not to tell Poppy that she caused the Kingsman attack, to which he promises not to, before betraying her and exploding the factory, ultimately killing her.
- Charlie Hesketh - Ex-Boyfriend