The model began insulting the former Atomic Kitten singer as a response to a column in OK! magazine where Katona said that Lennard needed "psychological help".
Lennard branded Katona "vile" and used the hashtag "#peasant" in a long series of messages mocking her past drug battles, struggles with her weight and previous failed relationships, writing: "I think YOU need to start using contraception [and] get over [ex-husband] @BrianMcFadden."
She continued: "kerry katona thinks I need help.I've never laughed so hard in my life. Do they even have internet access at fat camp or rehab...wait where's she at??? (sic)"
Lennard then admitted to using drugs herself before becoming a parent, claiming she "left that behind when I had my son. It aint a cute look being on cocaine pushing a pram".
The model then claimed that Katona is the "last person I would take advice on parenting or mental well-being from".
Lennard was a controversial figure in the Big Brother house, labelling herself as the "Queen of the Damned" and getting into vicious arguments with fellow housemates.
Upon becoming the first person to be evicted from the house she denounced fellow housemates Danica Thrall and Rhian Sugden as "skanks".