Question 1
Is Leila the sister of Amelia?
(1) Leila is female and child of Lucas.
(2) Amelia is child of Lucas.
Statement 1 tells us Leila is female and child of Lucas. Statement 2 tells us Amelia is child of Lucas. Together they confirm Leila and Amelia share parent Lucas and Leila is female, so Leila is the sister of Amelia.