A list of siblings who vanished together — not family abductions. I do include sibs who vanished with their parents, though. Probably not complete; these are just the only ones I can think of and I’m too lazy to look for any more right now.
Jamal Abdul’Faruq, 7, and Basil Abdul’Faruq, 8 (not listed as he was found deceased three days later)
Deion Tremayne Akemon, 32, and William Larry Roland, 22
Lillian Annette Anderson, 11, and Mylette Josephine Anderson, 6
Monica Arellano, 7 and Victor Arellano, 2
Michael Anthony Bennett, 14, and Monica Renita Bennett, 15
Barry Michael Brown, 6, Brandon Mitchell Brown, 2, and Sheketah Michelle Brown, 10
A.J. Campbell Jr., 11 months, and Myrisha Faye Campbell, 3
Ignacio Dejesus Cantua, 7, and Maria Teresa Cantua, 4
Amy Lee Fandel, 8, and Scott Curtis Fandel, 13
Michelle Renee Giusti, 1, and Clara Arleen Giusti, 10 months (not listed as there’s no photo available)
Julie Anne Guthrie, 6, and Timothy Patrick Guthrie, 3
Sarena Natoya Glenn, 9, and twins Brent Nicholas Hughes and Brenttany Nicole Hughes, 4
Francisco Granados, 18, and Jose Martin Granados, 21
Joel Hoag, 13, and William Hoag, 11
Michelle Houchman, 15, and Mitchel Salomon, 9 (not listed as there’s no photo available)
Michael Lloyd Johnson, 10 months, and Sheri Lynn Johnson, 4
Faloma Luhk, 10, and Maleina Quitugua Luhk, 9
Katherine Mary Lyon, 10, and Sheila Mary Lyon, 12
Violet Bobbie Matory, 9, Ivy Matory, 12, and Yolanda Marie Williams, 7
Michael Mayfield, 6, and Pamela Mayfield, 5
Jonathan Mordoche, 8, and Mario Mordoche, 11
Crystal Lynn Ortega, 13 and, and Misty Dawn Ortega, 15
Daniel Borje Santiago, 7, and Noel Borje Santiago, 11
Betty Dolly Sodder, 5, Jennie Irene Sodder, 8, Louis Erico Sodder, 9, Martha Lee Sodder, 12, and Maurice Antonio Sodder, 14
Fannie Fawn Stewart, 1 and Jessie Flo Stewart, 2
Andrew Thompson, 8, and Everett Thompson Jr., 11
Reagan Cordell Uden, 10, and Richard Loren Uden, 11
Alan John Westerfield, 7, and Terry Lee Westerfield, 11
Diana Moon Yoli, 7, and Mark Eugene Yoli, 2 (not listed as there’s no photo available)
Jeremiah Johnson, 8, and Joshua Johnson, 10: Was a family abduction but their abducting father was found without them and has refused to say where they are. Beyond that I have no info.
Francheska Sugel Martinez and Misheila Isleen Martinez: Twins who actually disappeared six weeks apart (Francheska at age 12, and Misheila after their 13th birthday) but are believed to be together.
Billy Sena, 11, and Mary Lou Sena, 9: Not siblings but cousins.
Alexander William Skelton, 7, Andrew Ryan Skelton, 9, and Tanner Lucas Skelton, 5: Another case where the non-custodial parent made off with them, turned up alone and won’t say where they’re at. They’re probably dead.
John Umich, 3, April Stevens, 8, and Christopher Stevens, 10 (April and Christopher were found safe in 2012): This is family abduction case, but the mother had a warrant out for her arrest on charges of cruelty to a child leading to injury or death. I’m not sure whether the warrant is still active or whether she was located at the same time her other two children were.