Emily is married to Noah and they have a daughter named Sophia. Emily's brother, Lucas, is married to Mia and they have a son named Ethan. Noah's sister, Ava, is married to Jacob, and they have a daughter named Olivia. How is Mia related to Noah, and what is Sophia's relationship to Olivia? Respond very briefly.
Mia, being the wife of Lucas (who is Emily's brother), is Noah's sister-in-law, because she is married to Noah's wife's brother. This makes her a sibling's spouse to Noah through his wife's family. Sophia is the daughter of Emily and Noah. Olivia is the daughter of Ava and Jacob. Since Ava is Noah's sister, this makes Olivia the niece of Noah. Therefore, Sophia and Olivia are first cousins, as their respective parents, Emily and Ava, are siblings.