Taylor Piliae and Pele Faletolu together. Photo / InstagramShe shared a short clip from an ultrasound and a photograph her sister took with the teenager.
Many people have commented on the post, including one person who wrote: "A mini him to guide your sister through life!"
The ultrasound showing the girls' pregnancy. Photo / InstagramAnother person said: "That was his biggest goal, to become a dad."
A third person commented: "(He) left a piece of his heart with her."
In a separate post, Piliae said she was "beyond in denial and lost for words" over the boy's death.
People close to the teen gathered to commemorate his life. Photo / TikTok"Fly high my beautiful brother. You didn't deserve any of this," she wrote.
"God bless your beautiful soul, may you rest easy and in peace. Love you my brother."
In an earlier post, she said she did not have the words to describe her pain.
Uati "Pele" Faletolu was remembered in a candlelight vigil. The teen died Monday evening from a stab to the chest. Photos / TikTok"All I know is I would never wish this pain on anyone," she said.
"We are all in pieces knowing you've left the earth.
"We will forever celebrate you for being the most bubbly, outgoing person.
"You'll definitely be missed and remembered by your dry jokes and loud laugh."