The Saturdays and JLS members will get married at Blenheim Palace next month, the birthplace of Sir Winston Churchill.
The couple are said to have spent thousands of pounds on the historic 18th century mansion for their wedding in July.
"Rochelle fell in love with Blenheim when she went to see it and loves the history of the place," a source told The Sun.
"The gardens are beautiful and she can't wait to have her wedding pictures done surrounded by her nearest and dearest. They are going all out for the wedding. And their families are tickled pink by the Winston Churchill connection."
Winston Churchill was born in one of the bedrooms of Blenheim Palace in Oxfordshire in 1874.
Marvin Humes was photographed handcuffed to a dwarf during his stag-do weekend with his JLS bandmates last month.