Okay, so I'm writing a fantasy novel where the main characters' mother dies right at the beginning. It's not really integral to the story, but it's more of a way to bring the brother and sister together for a moment. I don't want to deal too much with the grief, since it's not what the story is about. So how do I sort of blow it off yet not make them look heartless? It's there a way to do that or should I try to rewrite it so there is no mother? (Maybe she died years ago or something). Also, the father died a long time ago.
You don't necessarily have to write about the grief if you feel it's unimportant. You can just allow it to be in the background while you focus more about the brother and sister. If you're writing in third person you have the ability as the narrator to distance yourself from unimportant areas while getting more involved in the important areas. I'm not experienced in writing stories at all, but I think you should just experiment until you find something that works. Good luck!
I'm not sure exactly what you mean by "bring the brother and sister together for a moment." Are these characters adults who haven't seen each other for a long time? Are they teens? Children? Do they generally not get along or avoid each other? How is it that they're "not together?" If the mother's death is not important, don't put it at the beginning. You're highlighting it that way. Is there another way to "bring them together?" What is your goal or story need there? This is kind of a Chekhov's gun situation here.
I think you might struggle unless they hated their mother. A parent's death is always massive. A relative's mother recently died at 80 something, and he's still devastated about it. Maybe make it a lesser character, like a mutual friend, or cousin. Or have them re-united for a memorial of their mother who died a couple of years earlier. I really don't think that such a catastrophic event in a person's life can be used as in as small a way as you want to.
If the mother had a terminal illness rather than having died suddenly, one's grief can be resolving by the time the death actually arrives. You're still sad, but relieved the suffering is over.
What about a family estrangement/lingering illness? While grief would be present there'd also be other feelings involved that may override the grief if the estrangement was severe or the illness particularly lingering. Maybe that culture doesn't place much value on the parent-child bond so a lot of grief would be unusual. A funeral and the reaction to the death could be an interesting way of developing your culture without a lot of exposition. Ultimately it would depend on what best serves the plot.