Definitely. New fans often need a bit more background and context, and the light novel can provide that. It can be like a guided tour through Skyrim, showing the different locations, the relationships between the races, and the overarching lore in a more digestible way compared to just jumping into the game.
No. Fan fiction involving nudity goes against the general ethics and community standards of most gaming communities, including the Skyrim community. Such content is not family - friendly and can make many players uncomfortable.
In fanfiction, anything can happen. However, without specific details of the particular fanfic, it's hard to say for sure if Serena is pregnant. Some fanfictions might explore this plotline for the sake of drama or character development. It could add an interesting twist to the relationship between Ash, Serena and Lemon, but it also depends on the overall theme and direction the author wants to take the story.
There was this time when I entered an old abandoned house in Skyrim. I expected to find some treasure or a spooky enemy. But instead, there was a group of skeevers (the rat - like creatures) having a little party. They were all huddled around a small piece of cheese and they looked so cute and out of place. It was a very unexpected and funny discovery.
I was in a tavern in Skyrim and decided to challenge a drunk Nord to a drinking contest. I thought my character could handle it. But after a few rounds, my character started staggering around and seeing double. Then he passed out right on the table, and the Nord just laughed his head off. It was a really funny experience.
Serena could be a bit shy at first. She might blush deeply and look down for a moment. But then, she would look into Ash's eyes with love and admiration. She would tell Ash how much she loves him and how she has been hoping for this moment. She would accept his proposal gracefully, and they would share a tender embrace while their Pokémon friends cheer around them.
Her partner would be a very likely character to be involved. They could be the source of support, or in some cases, the source of conflict if they have different views on the pregnancy. Her best friends are also likely to be in the fanfic. They might be there to throw baby showers, give advice, or just be a shoulder to cry on.