Kelly Clarkson is thriving ever since Brandon Blackstock has been gone. Recently marking the two-year anniversary of her bitter divorce from the talent manager being finalized in March 2022, the 41-year-old couldn’t be doing better after moving with their two kids to New York City and starting the next chapter of her life. “She is doing really well,” a source recently spilled to a news publication of Clarkson. “She is happy that she left L.A. for N.Y. She has the primary custody of the kids and is a great mom.” The “Stronger” singer welcomed her daughter, River, 9, and son, Remington, 7, with …