Laura's would be bisexual, though even she isn't entirely sure towards which side she leans more. She's definitely always had an easier time hanging around guys and crushed on more than a few of them, but sometimes she just meets a girl that's so beautiful it just makes her go "whoa", lol.

With Margaret I would also say she's bisexual, though with a much stronger female leaning. There's also a slight nuance of demisexuality there too, given she really needs that emotional connection before she comes to see someone as romantically appealing. And given that she's had a far easier time achieving that with girls rather than guys thus far, it's shifted her preferance.

And as for Midna; she's purely Pansexual. Comes in part with the fact of her being a Spirit Medium. Very much so looks more so for the "who" in someone rather than the "what".