Their relationship would likely become more protective. Merlin would be constantly worried about Freya and the baby's safety. He'd use his magic more discreetly to safeguard them from any potential threats.
She might be completely overjoyed. With tears of happiness in her eyes, she'd immediately say yes and throw her arms around Merlin. After all, she loves him deeply and has probably been waiting for this moment.
For Merlin, in the fanfic, you can develop his character by showing his inner conflict. He has a great destiny and now he's about to be a father. He might question how he can balance his duties to Camelot and his new family. Freya, on the other hand, can be developed as a strong and wise mother - to - be. She could use her knowledge of nature to ensure a healthy pregnancy. She might also be the one to encourage Merlin to not be too hard on himself and to embrace this new chapter in their lives.
Well, a plot twist might be that Freya discovers she's pregnant with a special kind of magic - not just normal magic but something that is a blend of different magical realms. This causes a stir in the magical community and they have to deal with the politics and jealousy that comes with it. Also, Merlin might have to hide this fact from Arthur for a while as he fears Arthur's reaction to such a strange magical occurrence.
Love is a very common theme. Their relationship, whether it's a budding romance or a deep platonic bond, is often explored. Another theme is magic. Since both are magic - related characters, how their magic interacts or complements each other is frequently written about.
One great 'Merlin Freya Arthur' fanfiction is 'The Lost Bond'. It beautifully weaves the relationship between Merlin, Freya, and Arthur. It shows how Merlin's magic can be a bridge between Freya's otherworldly nature and Arthur's destiny as a king. Another one is 'Freya's Return', which brings Freya back into the story in a very unexpected way and explores how her presence affects the dynamic between Merlin and Arthur. There are also many on fanfiction.net that you can explore based on reviews and ratings.
One major theme is sacrifice. Given their circumstances in the show, many fanfictions show either Merlin or Freya sacrificing something for the other. For example, Merlin might sacrifice his safety to protect Freya. Also, the theme of redemption can be found. If Freya was seen as having a 'dark' side in some interpretations, fanfictions may explore her journey of redemption with Merlin by her side. And of course, the theme of adventure is also common as they go on various quests in these fictional stories.
One interesting Merlin and Freya fanfiction could be where they go on a journey together to find a magical cure for a plague that's hitting Camelot. In this story, they face many challenges and their relationship deepens as they rely on each other's strengths.
Well, it could start with Merlin finding Freya in a difficult situation. Maybe she's being chased by some dark forces. Merlin uses his magic to save her and in that moment of relief and gratitude, they share a kiss. It could be a very tender and innocent kiss, filled with the start of new feelings between them.
Well, perhaps Merlin would plan an elaborate, magical proposal. He might use his magic to create a beautiful, enchanted garden filled with Freya's favorite flowers and glowing orbs of light. Then, in the center of this magical place, he'd get down on one knee and present her with a ring made from a rare, enchanted gemstone that has special meaning to them both.