Credit: Instagram

Pop star and Weight Watchers spokesperson Jessica Simpson has officially gone from "before" to "after" — just check out the photo below!

Credit: Jessica Simpson on Instagram Photo: Jessica Simpson and Friend at Ashlee Simpson's Bridal Shower in Los Angeles in August 2014

The 34-year-old hosted sister Ashlee's bridal shower at her house this past weekend, but we wouldn't be surprised if Jessica got more attention than Ashlee, considering the swimsuit body Jessica revealed as the revelers partied by the pool.

"Oh yeah, girl," Jessica writes in the Instagram caption to this sunkissed snapshot, tagging a friend of hers. "We are proud to be in our bathing suits! #HardWorkPaysOff #WorkoutPartnersForLife"

We'd certainly agree! The In This Skin singer looks thin and toned, with admirably muscled legs. You wouldn't even know she has given birth twice!

Meanwhile, Ashlee is on the verge of marrying actor Evan Ross — and we hear it'll be a Labor Day weekend wedding. If so, she and her older sis will have had their weddings within two months of each other as Jessica married Eric Johnson in July.

We're assuming all eyes will be on the bride at that time if they weren't at the shower!

What do you think of Jessica's transformation? Are you as envious as we are over her killer physique? Let us know in the comments below.

Credit: AOL Photo: Jessica Simpson Busts Out of Her Bathing Suit (VIDEO)
Dan Clarendon is an assistant editor at Wetpaint Entertainment. Follow him on Twitter and Google+!