Shelley has been a champion for children and public schools throughout her time in the State Legislature. From 2013 to 2017, Shelley served as the Chair of the Assembly Education Subcommittee on Students with Special Needs. During this time, she advocated for and ensured that schools serving the state's most vulnerable students (Special Act, 4201, 853, and 4410 Schools) received increased funding from the state. While representing the City of Yonkers in the Assembly, Shelley prioritized delivering for the city's 26,000+ public school students. In 2019, after being re-elected to the State Senate, Shelley was appointed to serve as the Chair of the State Senate Education Committee. One of her first achievements was the passing of the APPR bill which decoupled teacher evaluations from an undue reliance on state standardized tests. She continues to work with her colleagues to deliver the resources and policies school districts throughout the state need to provide a quality education for every child, regardless of zip code. Most recently, the adopted budget began the long sought full phase-in of Foundation Aid to be completed by the 2023-24 budget and significantly expands PreK outside New York City. Prior to being elected as a member of the State Legislature, Shelley served as Chief Counsel to the New York State Senate Democrats, where she helped draft critical legislation to reform Albany ethics and protect taxpayers.

Before serving as Chief Counsel, Shelley was a Senior Counsel at the National State Attorney General Program at Columbia Law School, where she focused on health care and labor law rights. For over seven years, she was Vice President of Government and Community Affairs at Continuum Health Partners, one of New York City's largest teaching hospital systems, working to protect Medicaid and Medicare services and improving the relationship between New York City's diverse communities and the hospital system.

From 1982 to 1994, Shelley was an Assistant Attorney General in the office of New York Attorney General Bob Abrams where she handled major reproductive health litigation. Shelley served in the Civil Rights Bureau, as Chief of the Westchester Regional Office, as the legislative liaison for the Attorney General and ultimately as a senior advisor to the Attorney General. As an Assistant Attorney General, Shelley fought to protect civil rights for New Yorkers and to broaden laws protecting consumers and tenants. Shelley received a JD from SUNY Buffalo School of Law in 1979 and a Bachelor of Arts from UCLA in 1975. Shelley lives in Yonkers with her husband of 36 years, Lee Smith. Shelley and Lee have three adult children - Aaron, Julia, and Arthur Smith -- and five grandchildren.