The pair will return to the cobbles after a holiday in Miami but, will become caught up in a drugs mule storyline when Rosie brings back a package of illegal substances.
Speaking about her return on Loose Women today, Helen explained: "She's back with this package and it's really innocent looking, and she doesn't realise what has been planted on her by her boyfriend.
"She ends up getting her sister (played by Brooke Vincent) involved even though she doesn't mean to get herself into trouble."
The actress said she was "very excited" to be reprising her role and was pleased that Rosie was a much nicer and calmer person this time around.
Helen Flanagan reveals the Coronation Street storyline she hated playing as Rosie Webster
Helen appeared on today's edition of Loose Women
I didn't enjoy it when they played her cattier because it was hard to play
When asked by Linda Robson if she had requested Rosie was made into a more caring person, Helen revealed that writers chose to change her character without asking.
"I didn't ask for it," she explained. "But they wrote me more in that way."
She added: "I didn't enjoy it when they played her cattier because it was hard to play, I couldn't relate to it.
"I did want her to be nicer but obviously you don't want your character to be boring."
The 26-year-old went on to reveal that she could only really see Adam Barlow (Sam Robertson) as a love interest for Rosie.
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Helen said she didn't like playing Rosie Webster when she was 'catty'
Helen Flanagan's sexiest pictures
Tue, November 15, 2016
Coronation Street star Helen Flanagan strips down to her bikini.
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Helen Flanagan shows off her toned tummy in sexy bikini snap
Sophie and Rosie Webster are part of a drugs mule storyline
"There's a kind of spark with Adam," Helen told the panel. "I think they're quite funny together but he's a ladies man.
"She's very glamorous so I can only see her with Adam because they suit each other and I can't see her with anyone else on the street."
Loose Women airs weekdays on ITV at 12.30pm.