The question is flawed. It assumes that only a Queen regnant sharing power with her husband or other partner could ever sign laws and other government documents in the absence of the male ruler. That is not the case. It was perfectly possible for a queen consort to sign sign laws and other government documents in the absence of her husband.
On 13 May 1888, Princess Isabel of Brazil signed the lei aurea or Golden Law abolishing slavery in Brazil. She was acting as regent while her father the emperor was in Europe for medical treatment.
Empress Isabella was the regent of Spain in 1529-1532 and in 1535-1539 while her husband, Emperor Charles V was away. No doubt she signed a number of bills into law.
At that time the rightful ruler of Castile, etc. was her mother-in-law Queen regnant Juan la Loca ("Jane the Insane") but she had been called insane by her father King Ferdinand II of Aragon and her son and co-king Emperor Charles V and locked away with no outside contact.
After Emperor Charles V came of age he put female relations in charge of the Netherlands; his Aunt Margaret widowed Duchess of savoy until 1531 and his sister the widowed Queen Mary of Hungary and Bohemia until 1555.
Emperor Henry V left his wife, Empress Matilda or Maude (later claimant of the English throne) as the regent of Italy from 1118-1119.
And there are many other examples of queens consort without any political power while their husbands are in the country ruling while their husbands are away.
Thus it would seem logical that Queens regnant who were co rulers with their husbands could sign laws and other important documents while their husbands were out of the country.
But of course the best answer would be actual proof of the procedure in specific cases.