The 25-year-old star announced the news on Instagram by posting a picture of her flaunting a glittering ring and receiving a kiss from Eason.
"We've decided on forever! #PerfectTiming," she captioned the photo.
The news comes less than three weeks after the couple welcomed their first child together, daughter Ensley Jolie.
Evans is also the mother to two sons - Jace, seven, with ex Andrew Lewis and Kaiser, two, with former fiance Nathan Griffith.