In the messages, Flack said it was "perfect" that Whitmore would be doing the show alongside her husband Iain Stirling, who narrates the series, and followed up the message with a series of love hearts.
Born in Enfield, Flack got her first TV break playing Bubbles on comedy sketch show Bo Selecta alongside Leigh Francis, before fronting the International Pepsi Chart Show and moving on to Channel 4's E4 Music.
Flack's family previously released an unpublished Instagram post she had written describing the stress of her arrest for common assault, while her former boyfriend Danny Cipriani also shared their final messages.
In her Instagram post, Whitmore, 39, said: "I got a new phone this month and as I was trying to download WhatsApp messages from my cloud loads of old messages came up.
The Irish TV presenter shared a photo of the pair together, along with a series of screenshots of their WhatsApp conversation, in which she told Flack she had been offered the Love Island presenting role.
