Wentzville, Mo. – Thirteen years ago, a 13-year-old girl disappeared from her Foley, Missouri neighborhood.

Bianca Piper would now be 26-years-old.

Bianca’s sister, Tiffany Piper marks her sister’s disappearance by milestones like birthdays, holidays and the birth of her two children.

"Life does have to go on, but you think about it every day, things that she misses out on and things that we wish we could share with her,” said Tiffany Piper.

Piper said she thinks about all the things her sister has missed over the years.

“Whenever she was 16 and she could have drove, being in high school and going to prom, having a boyfriend, starting her own family, holidays, just everything that we take for granted in everyday of our life,” Piper said.

Tiffany said her sister went for a walk outside to cool off, but she did not come home.

“The last thing that I said to her was, ‘thanks a lot, I'm going to have to finish up your chores now,’ and it seems silly, but still 13 years later, that's what I said last, instead of 'I love you,’” she said.

The Lincoln County Sheriff’s Department searched by horseback and with 4-wheelers. Search dogs tried to sniff out the trail too. Even though there were a couple of false alarms, ultimately there was no sign of Bianca Piper.

Tiffany said she thinks of her sister all the time, especially during life’s most precious moments.

“Her niece Abby, she is going to be nine in August. Every time she gets a wishbone in a piece of meat, or picks a dandelion, or gets to make a birthday wish, she wishes for her Aunt Bianca to come home,” Piper said.