Monday's edition of the BBC soap will see Vanessa have an emotional heart-to-heart with her partner Max Branning (Jake Wood) in the early hours, asking him whether he still loves his ex-wife Tanya (Jo Joyner).
After Max dismisses the suggestion, he soon leaves Vanessa stunned by popping the question. Despite still feeling uneasy over Tanya, it's not long until she delightedly accepts his proposal.
Discussing Max and Vanessa's current storyline, Lucker told This Morning today: "For the past year really, it's been kind of a drip-feed and now because I'm leaving in the autumn, everything starts happening now.
"She tries so hard to get his attention and she does everything for him - she's constantly cooking and looking after his kids and all that sort of stuff. Since Tanya's back on the Square, he just doesn't notice her anymore."
She continued: "Next week, I think you definitely see a much more vulnerable side to her, because she does hide behind all this hair and make-up and it is a façade. Obviously she is quite a vulnerable person."
EastEnders bosses have confirmed that Max and Tanya will embark on an affair in the coming weeks, meaning that Vanessa is likely to face heartbreak before her departure from the Square.
Lucker added: "On EastEnders, secrets don't stay secret for very long. We don't know for definite whether she will find out about the affair, but if she does, I can imagine that it will be very, very explosive."
The actress also confirmed that Vanessa will remain on screen until "September or October".
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Watch a behind-the-scenes EastEnders video starring Zöe Lucker below: