A possible plot could revolve around Zelda's pregnancy being a mystery in the fanfic. Maybe she discovers she's pregnant but doesn't know how it happened, as there could be some magical or unforeseen element at play. This could lead to a quest to find out the origin of the pregnancy. It could also involve Zelda having to hide her pregnancy from some of the more superstitious or fearful members of the kingdom who might see it as a bad omen. Meanwhile, Link could be on a side - quest to find something that would ensure a safe pregnancy and childbirth for Zelda.
Well, a plot idea could be that Zelda's pregnancy affects her powers. In Breath of the Wild, her powers are crucial in the fight against Ganon. If she becomes pregnant, perhaps her powers become unstable or even stronger in some unexpected ways. This could change the dynamics of the fight. Also, the fanfic could explore how the news of Zelda's pregnancy spreads throughout Hyrule. Different regions and races might react differently. Some might see it as a divine blessing, while others might worry about the future of the kingdom with a pregnant princess in such a precarious situation.
One interesting plot idea could be Zelda's pregnancy adding a new layer of vulnerability. The story could focus on how she has to balance her responsibilities as a future mother and her role in the fight against Ganon. For example, Link might become more protective, and this could create some tension within their relationship as Zelda still wants to be actively involved in the battle plans. Another idea is that the pregnancy could be a sign of hope for the kingdom. It could symbolize a new beginning and give the people of Hyrule something positive to look forward to during the dark times.