Pictures showed the smiling 95-year-old monarch holding an audience with the new ambassadors for Latvia and Ivory Coast.
The queen carried out the engagements from her Windsor Castle home to the west of London where Philip's funeral was held two weeks ago, and it was the first since a period of official royal mourning ended.
Francis concluded his message by invoking "the Lord's blessings of consolation and peace" for the queen and for "all who grieve (Prince Philip's) loss."
Philip, the Duke of Edinburgh, was admitted to the private King Edward VII's Hospital on Feb. 16 after he felt unwell and was given treatment for an unspecified, but not COVID-19-related, illness.
Since being admitted, the duke has been publicly visited only by his eldest son Prince Charles, the heir to the throne.
