Matt, Anna, Alex, Luke, Bart and Ben are parents, and all the options in this puzzle.
1. The first clue directly reveals information about Juliet’s parent (Anna) and also about the position of all the Bart’s children. Since Zita is in both main diagonals, she’s Bart’s child.
2. Juliet’s clue says that Ian and Penelope are twins and therefore have the same parent. Since all the Bart’s children are in the main diagonal (Camilla’s clue), Penelope can’t be his child. Instead, Sophie, Madeleine, Timothy and Bernice are all Bart’s children.
3. Sophie’s clue directly reveals Alice’s parent (Ben). Madeleine is adjacent to two Ben’s children, and two Luke’s children (Juliet’s clue). Since Ben’s children are never adjacent to each other (Tom, Mark and Hugo are adjacent to Alice), either Ian or Martin is one of Ben’s boys. Since Ian and Penelope are siblings, and no Ben’s children are adjacent, Martin is Ben’s son.
4. Since only Matt and Anna have twins (Martin’s clue) and one of Anna’s twins is in a corner (Bernice’s clue), Ian and Penelope have to be Matt’s children.
5. Luke only has two sons (Juliet’s clue) and both are adjacent to Madeleine. By Ian’s clue, non-twin siblings can only be adjacent diagonally, so Luke is the parent of either Tom or Mark, but not both, meaning that Hugo is his other son.
6. Hugo’s clue reveals that Matt has another set of twins (Ian and Penelope are the first) and that both children in that set are girls. Since twins must be horizontally adjacent (Penelope’s clue), Matt’s girl twin set has to be either Louisa and Colette, or Colette and Hermione. Colette is Matt’s child.
7. Alex has exactly three children, two daughters and a son (Timothy’s clue), and Colette is adjacent to all three. Since Mary and Hermione can’t be Camilla’s siblings due to being adjacent horizontally or vertically (Ian’s clue), Alex’s daughter is Louisa. This means that Colette’s twin sister is Hermione, whose parent is Matt. Oliver and Tom are vertically adjacent to Louisa, so her brother and the only son of Alex is Mark. Therefore, Tom is Luke’s other son.
8. Hermione’s clue says that Mary and Matilda are sisters. Anna only has two daughters (Alice’s clue) and one of them is Juliet, so Mary and Matilda can’t be her children. This means that Lucy and Simon are her twin set. All the Alex’s, Bart’s and Luke children have been found already, and both Mary and Matilda are horizontally or vertically adjacent to Matt’s children, so they have to be Ben’s daughters.
9. Ben only has one son (Simon’s clue) and five children (Zita’s clue). Four Ben’s children are revealed already – Martin (son), Alice, Matilda and Mary (three daughters). This means one of the two remaining girls in the puzzle is Ben’s child. It can’t be Iris, as she’s vertically adjacent to Matilda, so it’s Elizabeth. Only three answers remain, and all children of Alex, Bart, Luke and Ben are found. The parents of the remaining three have to be either Anna, or Matt. Since we’ve found both Anna’s daughters, Iris’s parent is Matt. Paul is horizontally adjacent to Iris, so he’s Anna’s boy. Anna had exactly two boys (Lucy’s clue) and both have been found (Paul and Simon), so Oliver’s parent is Matt.
