How to Show Half-Siblings in a Genogram
Half-siblings are the single most-asked genogram structure question — and the rule that unlocks it is simple: in a genogram, every child is connected to each parent individually. Half-siblings are two children whose parent-child lines meet at exactly one shared parent.
The notation
The rule
Draw each child’s descent line to their own biological parents. Full siblings hang from the same parental pair; half-siblings hang from one shared parent, with the other parent (if shown) connected separately. There is no special “half-sibling line” — the structure itself communicates the relationship.
Common mistake
Connecting the half-sibling to the couple’s marriage line, which wrongly makes them a full sibling. If a child was added under both parents by mistake, delete the parent-child line to the non-biological parent — the structure then reads correctly.
How to draw it in GenogramAI
- 1Select the shared parent (not the couple) and add the child from that parent
- 2If the other biological parent matters, add them as their own person, connect them to the shared parent with the right relationship (divorce, past partner), and connect the child to them too
- 3Added a wrong connection? Click the parent-child line and delete just that line
"Maria is my mom’s daughter from a previous marriage" — the AI builds the half-sibling structure for you.
Frequently asked questions
Is there a special symbol for half-siblings in a genogram?
No. Half-siblings are shown structurally: each child’s parent-child line connects to their own biological parents, so two children sharing exactly one parent are read as half-siblings.
How do I show half-siblings who share a father but have different mothers?
Connect both children to the father. Show each mother separately, connected to the father with the appropriate relationship line (marriage, divorce, or past partnership), and connect each child to their own mother.
Why does my software keep giving the child both parents?
Most tools default new children to the selected couple. Add the child from the single shared parent instead, or delete the incorrect parent-child line afterwards — in GenogramAI, click the line and remove it.
Draw it correctly, automatically
GenogramAI renders standard notation for you — describe your family and the symbols come out right.
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