Mary pondered all these things in her heart.
Lets do some pondering.
During bible times, a widow losing a son meant losing her life. Only men could earn a living therefore a widow could only live on what people spared to give her.
The prophet Elijah prayed that a widow's son be brought to life and Jesus Himself at Naim touched the coffin of the son of a widow to also bring him back to life.
In these instances, God healed and brought back to life.
When Jesus died, He took away the Blessed Mother's life, made her a widow on our behalf, so that we may live. We are all dead through sin and Jesus saved our lives by dying on the cross. In so doing, she became our Mother, we who were brought back to life are God's adopted sons and daughters.