Donna's practice focuses primarily on U.S. (federal and state) and international regulation of energy markets; energy transactions; and energy project development. In addition to representing clients before the Federal Energy Regulatory Commission (FERC), she represents and counsels clients with respect to regulatory issues and requirements arising in project finance and acquisition transactions and advises clients of legislative and regulatory developments affecting energy companies.

From 1994 through 1999, Donna served at the U.S. Department of Energy (DOE) as a member of the Administration of President William J. Clinton. In her capacities as Director of the Office of Natural Gas Policy, Office of Policy, and Senior Director, Regulatory Policy, Office International Affairs, she advised the Secretary of Energy and other senior Administration officials on policy and regulatory issues associated with domestic and international energy markets.

Donna also played a key role in implementing the Clinton Administration's policy of promoting trade and investment in global energy markets. She was the principal author of the Asia Pacific Economic Cooperation (APEC) Natural Gas Initiative, which was endorsed by APEC Energy Ministers, Trade Ministers and Leaders in Okinawa, Japan, in 1998. Donna has advised numerous governments on natural gas and electricity law, policy and regulation; including Argentina, Australia, Bangladesh, Bolivia, Brazil, China, the European Union, Germany, Indonesia, Japan, Mexico, Mozambique, Namibia, Peru, the Philippines and Russia. For example, through the Gore-Mbeki Binational Commission's Energy Committee, Donna assisted the government of the Republic of South Africa in drafting gas policy, regulation and that country's first downstream "Gas Act."

At DOE Donna also advised the Office of the U.S. Trade Representative in a variety of international trade negotiations involving energy issues, including the APEC Early Voluntary Sectoral Liberalization (EVSL), the U.S.-Japan Enhanced Deregulatory Initiative, and the World Trade Organization General Agreement on Trade in Services (GATS) negotiations on energy services.
At DOE, she was Co-Chair of the annual DOE-National Association of Regulatory Utility Commissioners (NARUC) Natural Gas Conference from 1995-1998.

From 1981 through 1987, Donna served with the FERC. As a Trial Attorney in the Office of the General Counsel, Gas and Oil Litigation, she prepared and presented Commission staff positions in litigated rate and certificate proceedings arising under the Natural Gas Act. As an Attorney-Adviser in the Office of the General Counsel, Electric Rates and Corporate Regulation, Donna prepared Commission orders and rules in proceedings arising under the Federal Power Act, including electric utility rates, utility mergers, dispositions of utility assets, issuance of utility securities, with particular responsibility for issues relating to antitrust and corporate regulation. As an Attorney Adviser in the Office of Administrative Law Judges, she prepared initial decisions and orders in natural gas, electricity and hydroelectric cases.