A Consecration Covenant
The Missionaries of Charity, founded by Blessed Mother Teresa of Calcutta has a consecration covenant with Mary. In it we read that we give her 12 duties including giving her all we have, placing total dependence on her and being faithful in prayer. Mary's duties to us then include giving us her spirit and heart, possessing and transforming us and purifying our actions.
Read the full list of duties on page 80. It is a beautiful exchange.