Call the Midwife exclusive: Molly Vevers reveals what it's like to play new nun Sister Catherine

“It’s exciting joining something that’s so loved. Once I got the part, I watched it from the beginning and now I’m a superfan! There’s something magical about birth and the show’s about love in all different ways – family love and friendship and community love – but it’s hard-hitting too. I also used to be a nanny between acting roles, so being around babies was a part of this job I was excited about!”

“She’s been a nurse in a children's hospital so she has an affinity with children. And she’s bright, cheerful and capable with a sense of humor, but she's also navigating whether it’s the right decision to enter into the life of a nun and she’s wrestling with that sacrifice. She's from a close family, and although it’s her calling, it's difficult to go against their wishes…”

“Midwifery’s another calling for Sister Catherine, but Gail’s is a sensitive case, so she learns how to care for her, it’s not just about the medical side. But she gets her sleeves rolled up, and she's shadowing Nurse Crane [Linda Bassett], who’s a brilliant midwife.”

“Yes, I think it was my second day! Those scenes are technical and all about camera angles and you want to look like you have medical knowledge, but you’re learning on the hoof and I’m also squeamish! In rehearsal, a prop hand brought out fake blood and an umbilical cord and I thought I might faint, but I was fine!

“Sarita [Montagu], our consultant midwife, was brilliant though, I soaked up everything she said. I watched Linda Bassett too – she was so caring towards Louise, who played Gail, because it's scary [for the guest stars playing labouring mothers] doing birth scenes.”

“Sister Monica Joan [Judy Parfitt], because she also had this calling to become a nun, and her family weren't supportive. She’s a grandmother figure and provides Sister Catherine with emotional solace. Judy's amazing to act with.”

“Yes, everybody! It's scary joining when everyone knows each other. I thought, ‘How will I fit in?’ But they all reached out with open arms. Linda even bought me a plant, which was lovely!”

“When I got the part, I watched documentaries and read books about women of a similar age nowadays who decide to do this [become a nun]. Because I think sometimes when nuns are represented in film and TV, they're almost like saints, whereas I was really interested in the fact that this is a real woman of my age and she's not perfect. She's got all these doubts and normal things going on. I find that really interesting.

“I also read a book with stories of what it's like to be a midwife now. That was really useful, because, you just want to try and make it as real and human as possible. I also used to watch lots of One Born Every Minute, so I tried to channel some of that!”

“As a postulant, she has a veil, but you still see my hair. The actors playing the other nuns said, ‘Enjoy that, because the full habit muffles your hearing!’ I also have to wear a big cross and once I put that on, I was like, ‘I shouldn't really swear now!’ I like the grey dress though. I thought, ‘Could I wear this in my normal life?!’”

“It’s heavy! And the midwifery bag weighs you down. One day Jenny Agutter [who plays Sister Julienne] and I were cycling into shot, and we nearly crashed into Fred [Cliff Parisi] when he was working as a lollipop man!”

“Because I'd become a fan after watching the show every day, my mind was just blown with Nonnatus House! I'd expected it to be a set in a big studio with different fake rooms. But it really is this amazing old house – haunted some people say – and you can get lost in it. There are stairs that you've not seen before, they go to different places and head off along corridors or down into the basement.”

“I wish I could say that! But Jenny found this origami book from the 1970s and wrote a lovely message in it welcoming me. I haven’t learnt any origami yet, but the book is treasured.”