Option A: Sumire is born sooner a year or so younger than Naruto either having her or both have a summoning contract with Nue later through the story? Happy life for Sumire and Nue is in the story.
Option B: Sumire isn't born earlier and Nue is in the story and don't worry even if Naruto has a contract with Nue he will make sure Nue has one with Sumire.