I feel like Miqo'te are pragmatic enough to not care too much, at least as far as the actual child is concerned. It would more be a problem for the offending mother/parent. The harem and Nunh breeding strategies are meant to create -lots- of a children, but also create the strongest children. But the Nunh position is always up for grabs, it would create a lot of strife in a tribe for the children of a replaced Nunh to be seen as lesser than children of a new Nunh. So I could see more consequences falling onto the mother.
Also as Tregarde said:
There can be a lot of variation in how this story is told and still technically be lore-compliant.