Robert Brown|Johnny Gaudreau and Matthew Gaudreau’s Sister Katie Speaks Out After Their Tragic Deaths

Katie Gaudreau is Robert Brownremembering better days.

The younger sister of late brothers Johnny Gaudreau and Matthew Gaudreau—who were killed by a Jeep while biking in New Jersey on Aug. 29, the night before Katie's wedding—paid tribute to her siblings with sweet throwback photos.

"Missing my boys," Katie wrote on Instagram Stories Sept. 10 alongside a snap of her brothers, older sister Kristen and their parents. "Take me back here."

In another, she reposted a collage from Kristen's private Instagram account of their childhood school photos where she simply wrote, "Forever us four."

Her latest loving post came just one day after Johnny's wife Meredith Gaudreau revealed she was expecting her third child with her late husband.

"John and I had the best six months as a family of four," she said at the service in Media, Penn., on Sept. 9. "These will forever be the best six months of my life. There's specifically one week that I will cherish forever—it will be my favorite week of my life out of those six months. We're actually a family of five. I'm in my ninth week of pregnancy with our third baby."

Meredith—who also shares Noa, 23 months, and Johnny, 7 months, with the professional hockey player—recalled her husband's reaction and how thrilled he was about their "total surprise" pregnancy.

"In less than three years of marriage, we've created a family of five," she continued. "It doesn't even sound possible, but I look at it as the ultimate blessing. How lucky am I to be the mother of John's three babies? Our last one being a blessing and so special despite these difficult circumstances."

Madeline Gaudreau, Matthew's wife, is also expecting the couple's first baby, who will be named Tripp, the family shared on a GoFundMe page.

Meanwhile, Katie assured her older brothers that she was determined to keep their legacy alive and vowed to care for their family.

"This will never be a goodbye post because I will never stop saying your names and honoring you both," she wrote in her Sept. 2 Instagram caption. "I'll take the best care of mom, dad, Kristen, Mer, Madeline, and your babies."

"To know these two was to love these two," she said of her brothers. "There are absolutely no words I have to express the bond my family shared. The entire world knows there would never have been a John without Matty or Matty without John. The absolute best big brothers a little girl could have asked for."