Carol is the head of a hellraising criminal family, and her three children Barry, Dynasty and Kacey will be causing chaos at the school when they arrive as the latest recruits for headmaster Michael Byrne's pupil referral unit.
Digital Spy recently caught up with former Footballers' Wives and EastEnders star Zöe for all the gossip on her new project.
How have you found being part of the Waterloo Road cast?
"I've loved it. Initially I was very nervous about it, but that was mainly because the show is shot in Scotland and at the time when I was due to start filming, my partner Jim was working in Los Angeles for a couple of months. I was wondering how I'd manage to juggle the job with my childcare, which is the most important thing for me.
"But my parents and Jim's parents pulled together and were absolutely brilliant. That meant that I could go off, do the job and enjoy it without panicking about whether my 4-year-old daughter Lily was alright.
"The actual job has been great. They're a lovely cast at Waterloo Road. All actors bond when they get together for a show, but especially when lots of people are away from home. It's been fantastic, and I've got a couple more episodes still to do. It's six episodes in total - it started out as three and developed from there."
What was the main appeal of Waterloo Road to you?
"I think it was the fact that it's a challenge, because I'm playing such a different type of character. After I left EastEnders, lots of job offers came in for theatre tours, but as much as I love the theatre, those just wouldn't be appropriate for my circumstances because I want to put Lily first.
"When Waterloo Road came up, it was great that I could make it work with my family commitments. I've also enjoyed playing someone who's slightly controversial and very hard-edged."
What more can you tell us about Carol?
"Carol is the mum of three children - Barry, Kacey and Dynasty - and her husband Neil is in prison for armed robbery. They're a family who've had to move around a lot because the kids are often getting into trouble.
"You'll see that Carol's principles are slightly distorted, to say the least! She often finds herself on the wrong side of the law - that's how she's always been and how she was raised. It's also how she raises her own kids.
"They're a really interesting family and it's good fun to play. Wherever they go, they have a reputation that follows them. They'll stay somewhere for a couple of years, but then they'll have to move and start afresh. They're quite dodgy characters."
Even though she's an extreme character, is there a chance that viewers could warm to Carol?
"I think you can never tell how people are going to react until it's aired. When you're doing a long-running role like in Footballers' Wives or EastEnders, the audience really get to know your character as they follow all the ups and downs. I think the viewers then take a slightly more sympathetic point of view, because they see you at your lowest and then climbing back up again.
"With Waterloo Road, it's six episodes and it's quite spread out. I'm in episodes 11, 12, 13 and 19, and then later I'm back for 28 and 29. I just hope the audience are happy to pick up where they left off!
"Carol does some things that are not very nice, but you can see that she's a fighter and she's trying to keep her head above water. She's trying to survive as a single mum as she hasn't got a job, Neil is in prison and they're short of money. Carol would do anything to pay the bills and keep her family having a decent lifestyle - she does what it takes."
Is Carol still loyal to Neil even though he's in prison?
"She's incredibly loyal to him and they've got a really strong relationship. Neil has been in prison all through their married life, so I think Carol has got used to him being in there. She actually condones his illegal behaviour while it's happening, so she stands by him if it goes wrong and he gets caught."
Carol and her family are from Liverpool, so was it a challenge to take on a new accent for the role?
"Normally I just keep my own natural accent for roles, so it was a challenge. But I just went into the audition and thought, 'If it's really bad, I don't think they'll cast me in it!' Also, I'm working with the three kids who are all from Liverpool and have quite strong accents. That was great, because if there were any moments where I felt unsure about the pronunciation of something, I'd just run it by one of the kids.
"I think it's a lot about confidence and when I read the script, the voice that I spoke with seemed natural to that character. I'm hoping people won't think too much about the accent. Also, as the family have moved around so much, it's less concerning than if I was playing someone who was actually based in Liverpool."
Some of your previous characters have been quite glamorous. How would you describe Carol's appearance?
"Well, I would never call her glamorous - I think she's very rough around the edges! Because of the type of person she is, the look that we went for is very hard. She has a uniform dress sense, which doesn't really vary at all apart from her tops. Her jewellery and hair are always the same, so it's a big departure from my EastEnders character Vanessa.
"I didn't want Carol to be really glam, because I didn't feel like she was that type of person. There's no rollers, flowing hair or beautiful make-up."
Do we mainly see Carol at home or at the school?
"We never see her at home ever! You see Carol bringing the kids into school to introduce them, and then also when she's called in for various different reasons for each individual child. She's always causing some chaos down at the school."
Did your on-screen kids approach you for any advice?
"They're all really confident kids and they just got on with it. They were brilliant and such lovely kids. I gave some advice about other stuff, but that was just life advice because I'm older than them. In terms of the acting, they're so competent and absolutely great to work with."
Have you enjoyed filming at Waterloo Road's base in Greenock?
"Definitely - when it's a lovely day, the views are absolutely stunning and the buildings are beautiful. Unfortunately it rained quite a lot, so often it was quite grey! Greenock itself is a really lovely place.
"One funny thing was when I went into the school for the first time. It took me back to my own school days and made my stomach go really weird!"
Do you look back fondly at your time on EastEnders?
"Absolutely yes - it was a lovely job. I really loved playing that character and going to work every day. The only thing that was ever boring about that job was the M25 on the way home on a Friday night - sometimes it would take three hours! That was the only part that was in any way negative."
Would you ever go back?
"The door was left open and I think with EastEnders, you often see people go off and come back again. They reintroduce characters all the time, so you never know.
"At the moment, I'm still doing Waterloo Road so for the upcoming few months it's definitely not on the cards, but you never know. As I say, I loved playing the character, so it's something that I'd definitely consider if that offer ever came my way again."
> Read our spoiler for 'Waterloo Road's return episode
> Read more 'Waterloo Road' spoilers and news
Waterloo Road returns tonight (January 3) at 8pm on BBC One.