The Bel Ami actress has confirmed her engagement and revealed James Heerdegen popped the question "a couple months back", according to Us Weekly.
Christina met James on the set of her short lived TV series Pan Am, when he was working as a dolly grip and the duo first went public with their relationship in February 2012.
Christina called off her engagement to actor Owen Benjamin in 2009, and revealed her ideal man was: "Somebody smart and funny that I love being with.
"I've always said to people you should never let anyone change who you are because the only commodity you really have is your individuality."
The 32-year-old actress - who landed her first film role in Mermaids aged 10 - previously revealed she is happy to have left her twenties behind.
She said: "I'm so glad I'm not 20-years-old any more. I was in a hurricane. I'm a lot calmer now. I don't cause destruction for myself and others everywhere I go."
"I take things as they happen and I've learned to be calm about things, troubleshoot problem as they arise and make the best out of things."
But despite the mayhem, Christina - who suffered from an eating disorder in her early teenage years - wouldn't change a thing about her wild-girl past.
She explained: "It all kind of makes up the back story which is my life."
- BANG! Showbiz