"She admits she is an alcoholic.
"She says it's a good thing she's been in custody [because it's] enforced sobriety."
Mr Hall said Johnson wanted to deal with her alcoholism and accepted jail would be the best place to do that.
Judge James Weir said Johnson's latest reading was more than twice the legal limit and her alcohol readings had always been "really, really high".
"You are an accident waiting to happen," he told her.
He referred to another case in Hamilton yesterday when a drink driver was jailed for four years after killing another motorist.
"Members of the public are lucky you haven't had an accident and killed someone," he said.
The judge referred to a letter of remorse from Johnson and complimented her for acknowledging she needed help.
Johnson was also disqualified from driving indefinitely.
