In the English seaside resort of Eastbourne, she had made her comeback in doubles with Jabeur, third in the world rankings.
In the first round, the duo won against Sara Sorribes Tormo from Spain and Marie Bouzkova from the Czech Republic (2:6, 6:3, 13:11).
Williams and Jabeur were also victorious in the quarter-finals. Shuko Aoyama (Japan) and Chan Hao-ching (Taiwan) beat them 6-2, 6-4.
The American-Tunisian doubles could not compete in their semi-final against Aleksandra Krunic from Serbia and Magda Linette from Poland.
“We had so much fun!” Jabeur and Williams on double debut