The two actresses made their debut as the Mitchell sisters in July 2007. However, Womack announced that she is quitting her role as Ronnie Mitchell earlier this year.
"Oh, it's going to be awful," Simons told Digital Spy of life on Albert Square without her co-star. "I'm dreading it, I'm absolutely dreading it.
"She really is like my sister, and even though I'm sure it'll be fine as I have so many friends here, to think that she won't be around is really quite depressing! But I'll have to get on with it!"
With Ronnie currently in prison after admitting that she had swapped her dead son James for Kat and Alfie's child Tommy, it remains unclear how Womack's on-screen exit will play out.
Asked if she thinks Ronnie will be 'redeemed' before leaving, Simons confessed: "I'm not sure, but I don't think so. At the moment Ronnie doesn't want to be, and obviously Sam is leaving, but who knows?"
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