1000-Lb. Sisters Star Amy Slaton Shops for a Wedding Dress in Sneak Peek

Amy Slaton is getting married — again.

The 1000-Lb. Sisters star is already legally married to husband Michael, but she’s planning a real wedding on this week’s episode of the TLC docuseries.

In a sneak peek posted by The Blast, Amy prepares to try on a wedding dress she ordered online after unsuccessfully shopping in stores.

“I’m really scared to try on this wedding dress right now,” she says. “The other day I went wedding-dress shopping, and it was kind of discouraging that none of the dresses fit me. So I decided to order a wedding dress online, but I’m scared, because you don’t even know if it’s going to fit you.”

“And if it does fit, is it going to look good on me?” she wonders.

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The dress does indeed fit, and the bride-to-be is ecstatic.

“I’m relieved that the dress actually fits,” she says. “I can’t believe the day is finally here.”

The show, which premiered on New Year’s Day, follows Kentucky sisters Amy and Tammy Slaton, who are also YouTube stars, as they embark on a weight-loss journey.

Amy, 31, and Tammy, 32, weigh 406 lbs. and 605 lbs., respectively. They hope to undergo bariatric surgery — but they will have to lose enough weight to qualify for the procedure. The six-part series documents doctors’ appointments and healthy eating challenges and will ultimately reveal the final decision about their surgery.

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The sisters recently told PEOPLE they are happier and healthier since filming the docuseries last May. They cut sugar out of their diet in favor of low-carb, high-protein meals, and they have also discovered favorite exercises to incorporate into their daily routines. Tammy likes to swim, while Amy prefers to dance or go for long walks outside with her husband.

“I can go to the store and not worry about my looks because I feel good about myself regardless of what other people say about me,” Amy said. “I’m beautiful the way I am.”

Added Tammy, “I don’t feel like I have to wear a mask or hide my body when I leave the house anymore. I’m not afraid to let people see me.”

1000-Lb. Sisters airs Wednesdays (10 p.m. ET) on TLC.