"It was a challenging time and we thank all those who helped and supported us along the way. We can now move forward together with an eye on the future."
Tuariki Delamere, their immigration adviser, said he had called to congratulate the couple, who are living in Dunedin.
"I certainly have nothing over the years to suggest that they were not in a genuine relationship," he said.
Mr Singh came to New Zealand as an international student and met Ms Kessell at a hair salon in 2012.
They started texting and were married within three months.
Mr Singh told the Herald at the time that he was "madly, passionately in love" with his wife, but immigration officials did not believe their partnership was genuine and stable.
Immigration NZ said in a letter to Mr Singh that it was not convinced they had demonstrated their relationship was likely to endure because of the significant age gap and cultural differences.
Mrs Kessell-Singh was asked in an interview how she felt about being older than her in-laws.
She said: "I don't give a stuff ... I am 21 in my mind. It's not about the age, it's about who you like. Age is not relevant."
Mrs Kessell-Singh has a 39-year-old son from an earlier marriage and maintains Mr Singh did not marry her to get permanent residence.