Should one commend one's soul to Mary as is done in the prayer you mentioned? Shouldn't you commend your soul to Jesus?
Commending your soul to Our Lady was taught by St Louis de Montfort - one of the greatest Mariologist in 2000 years of Church history who has influenced many Popes in their spirituality and understanding of Our Lady. His motto is "To Jesus through Mary." Consecration to Mary takes you into the arms of Christ.