The 28-year old, who defeated former champion Ronda Rousey
in just 48 seconds last month, says she hopes to start a family with her partner, fellow UFC fighter Nina Ansaroff.
Nunes became the UFC's first openly lesbian champion when she submitted Miesha Tate in July last year to claim the women's bantamweight crown.
"I think there is a time for everything, you know, in this life," Nunes told CNN's World Sport show.
"I want to defend this belt as long as I can, maybe three more years, and retire. Because we want to start my family. I want to be healthy to see my kids grow, you know?"
'I'll be a better champ than Rousey'
Right now, however, it's UFC business as usual for Nunes, who is still basking in the glory of dismantling the popular Rousey.
A bronze medalist in judo at the 2008 Beijing Olympics, the American held the UFC division's No. 1 spot for a record 1,074 days between December 2012 and November 2015.
But her long-awaited comeback bout against Nunes didn't even last a minute, as the Brazilian landed 27 punches in quick succession.
"I've been training for Ronda Rousey for so long and I finally got the fight and it went exactly the way we've been training," Nunes said.
"I think I will keep this belt for a long, long time. If she wants to come back, it's up to her. But I will be a champion forever and I will be a better champion than Ronda Rousey."
Nunes, nicknamed "Lioness," was born in Salvador in the state of Bahia. Now based in Florida, she has a fighting background in boxing, judo, karate and Brazilian jiu-jitsu.
"I will be ready for every single opponent that steps in front of me, and be the best. You know, I want to be better this year than I was last year -- and I will be," she added.
"I wanted to be a champion. I always wanted to be a fighter and I'm never going to lose my focus. Everything that happened in the past for me makes me realize how focused you have to be in this sport, and I will be until I retire."