The former Sabrina the Teenage Witch star lost 40lbs with Nutrisystem, unveiling her new toned body in April.
Speaking at the time of her big reveal, the 38-year-old said she hadn't felt confident in a bikini for 10 years, and that she wanted to slim down for her husband and family.
'My husband takes care of himself for me so I need to return the favour too. I try to look good for him,' said the star.
And it seems Melissa certainly isn't a yo-yo dieter, proving she has kept the weight off months later with this latest lake photo.
Posing with her husband Mark Wilkerson and their three sons, the star stands knee deep in Lake Tahoe, which lies on the border of California and Nevada. Beaming under a large sunhat, the blonde actress looks happy and content spending her day in the water.
'Lazy day on the river! Family time before heading to a kick ass job next week' Melissa wrote.