Viewers will see the pair's wedding day arrive next week, but whether they will actually tie the knot remains to be seen as Michael (Steve John Shepherd) gives his pregnant fiancée a huge ultimatum at the ceremony - she must rip up their pre-nuptial agreement or he won't marry her.
Brooks, speaking to TV Times about the twist, commented: "She feels really confused and shocked at that moment. Suddenly she starts to question his motives and wonders if he's marrying her just to get his hands on her money. She desperately wants to believe that he loves her and wants this wedding to go ahead."
The actress confirmed that she wants the pair to sort things out, explaining: "I love working with Steve, and what's great is that I think he and I have a long way to go in terms of Michael and Janine's relationship. There's a lot more to explore. They're both toxic and I love the fact that things are so complicated between them.
"I think this marriage, if it happens, will be really different to the previous three because Janine has grown up. It's the second time she's married for love and this time it's different because she's having a baby."
Last month, tabloid reports suggested that Janine will go into premature labour at the wedding.
Brooks continued: "I was so happy when I read the script for the wedding. It's very intense and although it was tiring to film, I loved doing it. Janine is very nervous and is determined not to look like an idiot in front of everyone.
"She's having these pains in her stomach, but the doctor tells her it's a bladder infection so she's not too worried about them. Labour now would be a disaster as she isn't due for 11 weeks."
EastEnders fans will see Janine and Michael's big day unfold next week on BBC One.