I don’t get it. Wouldn’t it be Lulu in both cases?
But if it's good at reasoning it should understand that if the name is a Boys name then it is not the 5th daughter.
Now the last daughter can be called anything, but because there is a vowel pattern it should pick Lulu to solve the puzzle, but that is the wrong answer in the original puzzle.
The dad of <Person> has 5 daughters. Four are listed off. So the answer for the fifth is <Person>.