Ashley Schaus, 23, from Santa Claus, Indiana, met Will Seaton in 2010. They met at a car show. Once they had gone on a few dates, Ashley introduced Will to her little sister, Hannah. There was no point in getting serious if Ashley’s sister didn’t approve of will. But Hannah did, and their lives were forever different.

“She has Down syndrome and diabetes, and I look after her and protect her,” Ashley told FOX 5. “To be with me, you must accept her and love her as well.”

“Hannah and I share a very special bond,” Ashley said. “We built our home close to Hannah, so that we can spend a lot of time with her while still having our own privacy.”

So when will decided he would ask Ashley to marry him, he knew that Hannah would be part of the picture. Literally. The proposal took place in a filed of flowers and both women received a proposal from Will.

“Before you knew it, he was down on one knee, asking her [Hannah] to be his best friend forever,” Ashley said. “It was the sweetest moment in my whole life watching Hannah be so happy and feeling so special.”

“We may not know what the future will hold for Hannah, and I hope that someday she finds a sweet boy, but for now, I am so thankful she got to enjoy that moment that every girl dreams about,” Ashley said.

Will and Ashley wed in October. Hannah will be there, too.

“She’s more than just a bridesmaid, she’s practically one-third of the wedding,” Ashley said. “Hannah is going to be the ‘best sister.'” And Hannah and Will are preparing their own set of vows.

“They will make promises to each other to always care for one another, share secrets, make jokes and go fishing, as that’s one of their favorite things to do together,” Ashley said. “Will and I will share our vows and we all three will walk out down the aisle together.”

“When Hannah was born and they told me I had a sister, I never would’ve thought that I would’ve shared my wedding day, my engagement, and my whole life with her, but now, under all the circumstances, I wouldn’t have it any other way,” Ashley said. “I want Hannah right by my side throughout everything and someday in the future, whenever Will and I start a family, I know that Hannah will be a big part of helping raise our child. She will be a great aunt.”