Zillow has never been in your house.
It doesn't know you redid the kitchen. It doesn't know the roof is five years old. It doesn't know you have a finished basement. It doesn't know the neighbor across the street put in a driveway that changed your property's appeal.
Online estimates are a statistical guess. They're usually off by 5–15%, sometimes more.
A real valuation comes from someone who actually knows the Lincoln market and can look at your specific house.