It would be easy to assume that swagger and confidence are part of the McGregor clan's genetic make-up.

This week alone, UFC champion Conor rented out amusement park Funderland for the night, and then stripped off on stage with billionaire Richard Branson.

But Conor's sister Erin doesn't share her brother's boundless self-assurance.

Last Sunday night, once the first episode of 'Dancing with the Stars' had drawn to a close, Erin was overcome with emotion and broke down while talking to reporters. This week, as she rehearses her salsa dance with partner Ryan McShane (below), she seems calmer.

"I got very emotional on Sunday because stage fright was real for me," she explained.

"And I felt that I let myself down. The first few nights this week I didn't really sleep."

Erin (36) is used to competing as she used to be a body builder, but she was unprepared for the spectacle of the show.

"I have never had to perform a routine with all the cameras on you and everyone's looking at you. I was taken aback.

"I'm trying to bring out that inner fighter in me," she said. "I know there is a little fighter deep down…I'm trying to think of that and not let the fear in." The mother of two says her confidence took a knock following the birth of her son Harry (17 months).

"After I had Harry, I spent so long at home with him and I loved that. And I was so grateful that I was in a position I didn't have to go back to work. But after 11 months… I became very anxious… I lost that [inner fighter]."

This week is the first 'Girls Week' and Erin will be competing against comedian Deirdre O'Kane, broadcaster Maia Dunphy, model Alannah Beirne, camogie champion Anna Geary, and publishing powerhouse Norah Casey.

Asked who she reckons her biggest competition is, she replies: "Myself. If I can get over my stage fright and my own insecurities, then that's as good as the Glitterball trophy. I can't ask for any more than that."

Tomorrow night all the McGregor clan, including Conor, are due to be in the audience in Ardmore.

Erin's brother has been a hot topic of conversation in the lead-up to the competition. This week, when asked if Conor had been giving her tips on how to succeed, she said he had, before adding: "But it's a different type of competition and I'm not Conor."

Despite being constantly quizzed about her brother, Erin doesn't feel like she's living in his shadow.

"I never get frustrated. He is an amazing character and an inspirational person to be around," she said.

"I get it because when I am in his company, I feel it. He has the X factor - and I'm very proud to be his sister. I have been very lucky to watch someone live their dream."

Dublin contestants tend to flounder in Irish phone-in shows - Dubliners are not typically loyal TV viewers.

But Erin seems unfazed by the statistics.

"I know I have people behind me," she says. "I'm doing this for all the mammies in their housecoats watching TV like I was.

"And for everyone in Crumlin."

'It's a different type of competition and I'm not Conor' - Erin McGregor on brother's advice ahead of DWTS'Kev had to be comfortable with me taking DWTS on because he's running the house while I'm dancing' - Anna Geary