Third Eriksen Child
This is the third child of Marshall and Lily, It is mentioned in the series finale that Lily is pregnant with her. This child is mentioned in the future preview in the finale episode. Barney is the first to say he knows Lily is pregnant with this unamed and unborn child.
- Parents: Marshall and Lily
- Brother(s): Marvin W. Eriksen
- Sister(s): Daisy Eriksen
- Grandparents: Marvin Eriksen Sr. (Deceased) , Judy Eriksen, Mickey Aldrin, Janice Aldrin
- Uncle(s): Marvin Eriksen Jr, Marcus Eriksen, Ted (honorary), Barney (honorary)
- Aunt(s): Ashley Eriksen, Robin (honorary), Tracy Mosby (honorary)
- Cousins: Martin Eriksen, Penny and Luke Mosby (honorary), Ellie Stinson (honorary),
- The baby was never seen, and its name was never revealed. Lily's pregnancy is mentioned when Barney and Robin reveal their divorce.
- Since Lily and Marshall "told" everyone she was pregnant in May 2016, but it was still early she would probably have been born around the beginning of December 2016.
- The baby is believed to be a boy. Marshall once refers to the baby as a he, in part two of "Last Forever". He states that they "Can put his crib in the shower" revealing that the third child is a boy.