The 43-year-old actress has dated a string of famous men - including the late Heath Ledger and singer Adam Ant - but admits she has never been in a rush to wed because she is content with her own life and doesn't need a guy to validate her existence.
She said: "I want to make the right choice. I feel I have a happy, good life, so someone would have to make my life better.
"We're not economically dependent on men. We're free. You can choose to be with someone or to be on your own and this is great."
The 'Hangover Part III' star - who shot to fame with roles in films such as 'Boogie Nights' and cult TV show 'Twin Peaks' - is ecstatic to reprise her role as former call girl Jade in the comedy sequel, but she worries about the amount of movie roles available to women in Hollywood.
Heather plans to make her own movie as a result, blasting the "sexist system" in the movie industry.
In an interview with The Sun newspaper, she said: "There aren't so many good parts for women. I think that in any given movie, 75 per cent of the roles are for men. Overall, I think it's a very sexist system.
"I just wrote a script that I want to act in and also produce. It is about how hard it is to make movies about women. It's all about my own frustration in the business, I guess."