They might start by decorating the nursery. Hal could paint the walls while Maggie picks out the furniture. They could argue a bit over the color scheme, like Hal wanting a more neutral color and Maggie preferring something more colorful.
One possible plot development could be the added pressure on the group. They would need to ensure the safety of Maggie and the unborn child in the dangerous post - apocalyptic world. This might lead to more cautious strategies and a greater focus on finding a more permanent and secure shelter. Also, it could create some emotional turmoil within the group, especially for Hal, as he would be worried about becoming a father in such a harsh environment.
Another plot could involve their families' reactions. Hal's parents might be overjoyed while Maggie's family could be a bit more reserved or even skeptical at first. This could lead to some family drama and interesting character interactions.
Their relationship could face strain. The stress of the pregnancy, combined with the constant danger in 'Falling Skies', might lead to arguments. For example, if Hal is too overprotective or Maggie feels like Hal isn't doing enough. But at the same time, they would also have a deeper bond because of the shared experience of expecting a child.
Well, without more context, it's hard to say exactly. It could be a fanfic that delves into a really strange and interesting concept. Since Maggie is a baby in the normal 'The Simpsons' universe, having her pregnant in a fan - made story might be a way to subvert the normal expectations of the show. It could potentially explore themes like family, growth, and change in a really unique way.
It depends on their popularity and the creativity of fans. If people are really into their characters and potential relationship, fanfiction could definitely exist.