The True Blood actress married co-star Moyer in 2010, and gave birth to the couple's twins last month.
In an interview with Red magazine, Paquin, who confirmed publicly she is bisexual two years ago, admitted some people question how her marriage and sexual orientation are compatible.
"I am a happily married woman and I married a man. I don't think that negates that aspect of my life, but obviously I wouldn't be with my husband if I didn't want to be married to a man," she explained.
"Some people find it odd that you can identify with a sexual orientation that is not straight and yet be married to someone of the opposite sex. They're like, 'Obviously it's not real if you're married to a dude'."
However, she said she does not feel the need to justify her relationship in light of criticism.
"That's not my problem. I'm like, 'Okay, if that's how you feel, there's nothing I can do about it'. I'm just living my life," Paquin said.
The 30-year-old also said realising her sexual orientation as a teenager was not an "Oh my God moment", adding: "It's just part of who I am."
Red is on sale Wednesday, October 3, 2012.
> 'True Blood' Anna Paquin 'isn't sure what kind of mother she'll be'
> 'True Blood' exec: 'Sookie, Alcide romance still possible'
> 'True Blood' gets shorter sixth season