Pope Francis replaced Benedict in 2013 (Image: GETTY)
The decision further strengthened Francis' growing appeal with liberals inside, and outside of the church, with Sister Becquart becoming undersecretary of the synod of bishops.
It sees Sister Becquart become the first woman to vote on church matters.
The move was hailed by secretary general of the synod, Cardinal Mario Grech, who said it showed Francis' desire to have "a greater participation of women in the decision-making in Catholicism" had been realised.
Critics claim Benedict continues to hamper Francis, and his bid to rid the Catholic church of its seemingly outdated traditions.
The spat between the two has left many observers fearing for the fate of the church - especially if Francis is unable to fulfil his mandate of dragging Catholicism into the 21st century.