American actress Mary McDonnell can boast a wealth of acting experience, including two Oscar nominations for Dances with Wolves and Passion Fish, and she’s currently winning critical acclaim for her starring role in US TV drama Major Crimes.

Mary, 60, didn’t always find the actor’s life so easy, and can still recall life as a budding actress in New York. “You are slamming around in subways, going into cold, dark theatres with your costumes over your shoulder, giving your best and getting rejected,” she says.

Mary doesn’t regret this learning curve. “These experiences build a kind of muscle internally, emotionally and spiritually that I cherish in my work,” she explains.

When comparing actors who had worked their way up to those who walked on to set with little or no experience, Mary says there is a noticeable distinction. “The difference is in confidence,” she says. “I have seen people over the years who are ill-prepared for the pressure they are under.

“And even though there may be a talent or a spark there, or whatever it is that got them cast, they really can’t deliver a nuanced performance and they don’t have the skills.”

Major Crimes is a spin-off from The Closer, where Mary had a recurring role as Captain Sharon Raydor. Her character takes the lead in this new show, which Mary describes as “a huge challenge”.

“There were moments when I thought, what have I done?” she admits. “How can we take this character and slowly turn her into someone who’s at the centre of this group, rather than the person who is talked about at the watercooler?”

Creating a strong female lead is important to Mary who believes there should be more inspiring role models for women. “I particularly think it’s really important right now,” she says. “Because girls are being bombarded with every kind of image and every kind of idea.” Mary has experience of playing strong female roles; she was First Lady in the blockbuster Independence Day and President Laura Roslin inBattlestar Galactica.

So, will McDonnell’s new series win over the die-hard fans of The Closer? She acknowledges that taking a well-known character out of its original context and creating a spin-off is always a risk. “We wanted to honour the fans, not turn them away,” she says. “We know how much these characters are loved. We wanted to get it right at all costs.”