The actress, who plays the fan favourite farmer's daughter, revealed that there are some "heartfelt moments" for the two characters after their wedding.
WATCH: Are you looking forward to season three?
"There are real heartfelt moments that happen between James and Helen that only happen when they're in the bedsitter on their own, and as the season progresses there are some things that are really tough for them to discuss and make them both feel really vulnerable," she told RadioTimes.com.
"Being able to do that in their own environment in the bedsitter sort of peeled off another layer, I think."
James and Helen became engaged at the end of season two and while many fans suspected that a Christmas wedding would occur in the festive special at the end of last year, they are having to wait until the new series to see the two unite in marriage.
Teasing the upcoming wedding, James actor Nicholas Ralph said: "So I can't say too much but when I read the script I was smiling like a Cheshire cat from start to finish. It's absolutely brilliant.
Rachel Shenton plays Helen in the series
"Not only is it everything that you would hope it would be - romantic and touching in points as well - but it's also very funny. It's a really funny, funny script as well."
So, what can fans expect from season three?
The official synopsis reads: "Series three begins in spring 1939. Some big changes are happening at Skeldale and everyone has to learn how to adjust. James enters into a new stage of his life with Helen and at the practice, where Tristan is now also a qualified vet.
James and Helen got engaged at the end of series two
"After being made joint business partner by Siegfried, James pushes to take on more responsibility via the Ministry of Agriculture’s new bovine TB testing scheme, but its unexpected challenges risk pushing him to breaking point. As a potential Second World War looms, all of our Skeldale family have to consider their purpose in Darrowby and beyond."
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