Herbert, who has four children from two previous marriages, said since the broadcaster came into her life, she has rediscovered joy.
"Simon is the most incredibly kind, loving man. His kindness has healed a multitude of things in my life. He has taught me so much about myself."
The couple met at Braemer hospital in Hamilton last September as they were both undergoing surgery.
"I couldn't afford to bump or move my arm and she was hunched over," Doull told Woman's Day.
"We just sat at my place and had a chair outside looking over the countryside. We'd drink wine, watch races and DIY TV, and talk and talk and talk. That was probably the best thing that could have happened."
Herbert is a cancer survivor and said the fact that Doull's parents had both died from cancer helped the pair come to terms with love and loss.
"Simon lost his mum quite tragically and he always felt from that point if he ever truly loved somebody, they would be taken away, so he made a decision he wasn't going to let that feeling ever happen again. I guess we've kind of healed each other."
Doull, who played 32 tests and 42 ODIs for New Zealand, commentates for SKY TV and has been part of the commentary team for the IPL since 2008.