On the day in question, the Crown alleged Joseph took the teen to the cinema, something mentors were encouraged to do to build trust.
The complainant told the court he and Joseph met up with the complainant's mother and spent the rest of the day drinking.
The court heard Joseph dropped the other woman at home and continued with the teen to Oakwood Manner motor lodge in Mangere where she booked a large studio room.
The boy told the court she persuaded him to join her in bed and the pair had sex.
Mr Pati accepted his client had spent the night with the complainant at the motel but there was nothing more to it.
"It was an extremely poor series of decisions but it doesn't mean she had sex with [him] on that night," Mr Pati said.
He told the jury the teenager had simply told a lie and been forced to follow through with it once the police became involved.
Crown prosecutor Evan McCaughan drew the jurors' attention to text messages between Joseph and the boy.
At one point, the court heard she told him she would give him "a big juicy kiss and a hug" and that she would probably be sacked if she told him how she truly felt.
The defence conceded text messages from Joseph painted a very negative picture but emphasised her inexperience as a counsellor.
"Are the text messages inappropriate? Absolutely. She's new, she's busy, she's overloaded, but she's naive," Mr Pati said.
Once Joseph was acquitted, Judge Gerard Winter said she could leave the court.
Outside court, Joseph spoke of her "absolute relief".
"My children, my family and my husband were directly involved in this and have been affected by this," she said.
Joseph said it was "excruciating" to hear lies being told about her in court.
She also thanked her lawyers, who struggled to contain their joy as the verdict was announced.
When asked whether there might be any path into social work in future, her answer was emphatic: "definitely not".
Joseph said she was now looking forward to a family trip to Rarotonga.
