(Church of Mary Immaculate, Stranorlar/Ballybofey, Co. Donegal, Ireland)

The Fifth Sorrow of Our Lady was when Her Son gave His life upon the Cross for the salvation of mankind.

"Our Beloved Saviour had instituted the Sacrament of Love [on Holy Thursday] that He might remain amid His children. He had poured forth all His Blood for us, and He wished moreover to bequeath us a legacy in the last Testament of His Love. But what more could He give us? He casts a compassionate look upon His tender Mother, who stands immovable at the foot of the Cross with His beloved disciple....'Woman,' says He to her,... 'behold your son!'...She does not refuse it, well knowing that she accepted for her children, in the person of John, all the followers of the Cross of Jesus, and that she was to become the beloved Mother of all Christians."

~ Don Gaspar Gilli, The Month of Mary, According to the Spirit of St. Francis of Sales, imprimatur 1890.

I've read elsewhere that when Our Lady gave birth to the Savior, she suffered no labor pains. He is perfect, and she had no stain of sin in her, so it makes sense. But when she became our Mother, on Calvary, she suffered immensely. 

He never gave her a moment's disappointment, but we disappoint her often. How comforting, though, that she never gives up on us. She accepted the mission of being the Mother of this unruly mob of God's children, and she just keeps picking us back up when we fall and encouraging us to try again. She never gives up on us, right up until the door of death. 

He truly gave us a wonderful gift when He gave us the only thing He had left as Man dying on the Cross -- His loving and beautiful Mother.