Create a family using initials. Some initials will be difficult to make combos out of, but it should be a fun challenge.
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Surname: Q .. X .. U .. Z .. Y
Mom: K C
Dad: C C
Daughter / Daughter twins: K C / C K
Son: C C
Daughter: K Q
Son / Daughter twins: X C / Z K
Daughter: X H
Daughter / Daughter twins: H Y / Y H