Ashley Schaus asks her 15-year-old sister Hannah, who has Down syndrome, if she feels pretty in the dress she selected at David’s Bridal. Ashley wanted Hannah to wear a white dress to her wedding so that she would stand out in her role as “Best Sister”, which Ashley coined to signify that Hannah was more than a bridesmaid.

"This day is as much about Hannah as it is about me," Ashley said. "She may not get the chance to get married, so I want to make sure she does get to have this experience." Before Will Seaton proposed to Ashley, he got down on one knee and asked Hannah to be his best friend forever.

Hannah read the book “The Adventures of Lilly and Hannah” to Ashley as they sit on Hannah’s bed at their Evanston home. Ashley writes personalized books starring Hannah and her pets to help Hannah practice reading.

Ashley rubs moisturizing lotion on Hannah’s face. Hannah has diabetes, which makes her skin dry out faster. Both Ashley and Will have learned to notice changes in Hannah’s blood sugar based on her behavior.

Ashley, Hannah and Will brainstorm ideas for Hannah's "tacky tourist" costume for homecoming spirit week at Heritage Hills High School as they dine on pizza at Noble Roman's. Hannah giggles as Will suggests sunscreen on her nose. The couple includes Hannah on most of their dates.

Hannah, left, and Ashley hold hands during Ashley’s bridal shower at Hatfield United Methodist Church. Ashley made Hannah a Best Sister sash, but when it was forgotten at home, she let Hannah wear her Bride sash.

Will chases Hannah with the fish she caught at a neighbor’s pond. For years, Ashley tried to teach Hannah how to fish with no luck. The first time the sisters went fishing with Will, he was able to teach Hannah in a matter of minutes.

Ashley helps Hannah apply deodorant after her shower. The two sisters used to shower together every night, but as Hannah has gotten older and learned the routine, Ashley now only needs to poke her head in to point out the different products. Following the routine — which includes doing their hair, brushing their teeth, applying deodorant and moisturizing —has helped Hannah learn the process and work towards increasing her independence.

Hannah paints Ashley’s toenails the same shade of red that Ashley had painted Hannah’s fingernails. Even though Hannah’s pedicure resulted in some excess polish on Ashley’s toes, she proudly wore it all day.

Ashley leans in to encourage Hannah as she says her best friend vows to Will during the wedding ceremony officiated by Rev. James England.

“You are my brother and my best friend forever,” Hannah said. “I promise to go fishing. I promise to tell funny jokes. I promise to care for you. Thank you for being in my life.” Will returned the sentiment in his friendship vows to Hannah.

Hannah feeds Will a piece of wedding cake as Ashley waits her turn to do the same during the wedding reception. In her vows to Will, Ashley said, “Hannah and I were a packaged deal from the start and you have loved both of us more and more each day.”

Ashley and Hannah relax in a hammock swing. Ashley and Will plan on building a house on the same property as the Schaus family’s home so that they are never far from Hannah.

"For as long as I can remember, I knew that Hannah was special," Ashley said. "And I knew that, as her sister, that I was going to look out for her.”