Biography

Wife of George Underwood. Referred to as "Mrs George Underwood" in 18630628FMS_WHS1.

Also seems to have written a letter to FMS (18630000CPUnderwood_FMS) in which she describes a slave and her children, and their plight in Maryland. 
Also appears in 18631013FMS_AWS - FMS recounts and encloses Mrs. Underwood's letter. 

Married to George Underwood and attorney in Auburn according to a landmark document put out by Cayuga County "The Underwoods were one of those families allied with William Henry Seward, as a law associate, professional, or Whig-Republican politician who became abolitionists and Underground Railroad supporters."
Seeing as Mr. and Mrs. Underwood both took part in Underground Railroad/abolition movements it makes sense that Mrs. Underwood would write a letter about a slave to FMS.