Emma did not understand how could someone in modern times like now could get married without love. She only read stuff like this in history books.
When the world was still divided by kingdoms ruled by royal families and noblemen, political marriages between the sons and daughters of the kings and nobles were indeed quite common. It was done so that their families could maintain their power and secure alliances.
But it was from hundreds of years ago. Now they were living in modern times. Even the kingdoms and royal families were no longer significant.
Although on Earth now there were still several kingdoms, the ruling families only served as symbols. They did not really have the power that must be maintained by political marriages. They could marry commoners and live like normal people.