Ashlee and Evan, 29, announced their engagement in mid-January, when they posted identical snaps of themselves on Twitter. "My baby love and I are ENGAGED!!! Hallelujah Hawaii !!!!!" wrote Ashlee referencing Diana's famous song, her huge engagement ring proudly on display.
This will be the second time that Ashlee has tied the knot. She was previously married to Fall Out Boy rocker Pete Wentz, with who she has a five-year-old son Bronx.
Jessica also used the opportunity to share several pictures of herself in a black swimming costume.
The blonde beauty showed off her toned physique which she gained through exercise and following the Weight Watchers program.
"Oh yea girl...We are proud to be in our bathing suits!! @baylormcg #hardworkpaysoff #workoutpartnersforlife" Jessica shared with fans.