nonparent
foster son
foster-son
adoptive sibling
bastard
noncousin
she could be his mother
jacket
nonfather
nondescendant
full-sibling
founder
singleton
folk
he could be her father
stranger
foster daughter
foster-daughter
sis
nonmother
sister
maternal cousin
whosiewhatsit
family romance
nonkin
noncomprehender
irregular double first cousin
sesquiple first cousin
irregular double cousin
unpaternal
unparental
sesquiple cousin
blood brother
preadult
nonchild
brother
half blood
non-relative
nonsibling
folks
only child
olds
sibling
stun
know-nothing
dukes
old
nonadult
biofather
semichild
nonsister
unparented
simpleton
simple
matrist
square
bucket head
natural child
lame
buckethead
stepparent
unteachable
fool
parentally challenged
misparented
do you have children
four oh four
paternal cousin
closed book
nonpatrial
lackbrain
grandparent
father-out-law
nuffy
divvie
brother german
mulatto
love child
disparented
ascendant
do you have any brothers or sisters
ascendent
uterine sibling
ancestor
root
great-uncle
grandfather
antecedent
agnate
analphabet
daddyless
patronym
confuter
orphan
aunt
blood relative
myth