The US Consulate in Paris publishes lists of English speaking and dual-qualified accountants and attorneys: France A - Z | Embassy of the United States Paris, France

Check the links for "Attorneys in France" (many are tax attorneys) and for "Tax Accountants in France."

Many of them are members of the various US expat groups, such as AARO or AAWE, if your friend is looking for personal references.
Cheers,
Bev