I think she's suggesting Miku is another of Satou's wives, ie, they're a community of moms with a bunch of Satou's kids. It makes sense given the context of Satou just coming by occassionally or men "throwing them away" when they're done.Did she just have an image of miku being her mom and satou being her dad?
None of you seem to understand, he's not locked up in there with you, you're locked up in there with him