The 19-year-old `Harry Potter` actress - who plays the title character`s love interest Ginny Weasley in the hit movie franchise - has reportedly got engaged to co-star Jamie Campbell Bower, who plays Gellart Grindlewald, after just six months of dating.
A source on the set of the final `Harry Potter` movies, `Harry Potter and the Deathly Hallows` - which will be split into two parts before it is released later this year - told the Mail on Sunday newspaper: "We are all absolutely shocked and surprised and can`t believe that Jamie has asked Bonnie to marry him.
"They met on the set of the movie and Jamie fell for Bonnie really badly. He says they are completely in love. It all seems very whirlwind, but they both say it`s the real deal."
Jamie, 21, is understood to have proposed to Bonnie last month, but details about their marriage plans are unclear.
The source added: "All he has told us is that he asked her to marry him and Bonnie said yes. `He is really pleased and neither of them seem to have any doubts that they are rushing in too soon. We have asked them if it is for real and they have said yes.
"They are both very professional, so when they are filming, there is no smooching or playing around. Also they are not really in the same scenes. Jamie is often on the set just to watch Bonnie and spend time with her between takes."
The news is said to be a shock to Jamie`s ex-girlfriend Zoe Graham, who split from the actor - who has the clothes designer`s name tattooed on his chest - shortly before he started dating the redheaded beauty late last year.
An insider said: "They split up last year and within months Jamie was dating Bonnie. He really wears his heart on his sleeve, and when he was dating Zoe he had her name tattooed above his heart.
"Zoe feels rather cast aside. It was a very serious relationship and he was always very proud of the tattoo. No one`s sure what he`s going to do about that now he`s with Bonnie."