Traditionally, the Church has accepted that Saints Joachim and Anne are the names of the parents of the Blessed Virgin Mary. That makes them God's grandparents.
Think of that for a moment. The Second Person of the Blessed Trinity had grandparents. If first century Jewish grandparents were anything like grandparents today, then God got some serious spoiling — if such a thing were possible. And Joachim and Anne were in the remarkable position of having a grandchild for whom, truly, nothing would ever be too good. When they said, "He's adorable!" they could mean it in the strictest sense of the word, for their Grandchild is the same Person whom we all adore in the Eucharist. When they said, "He's so cute! Couldn't you just eat Him up with a spoon?" they had no real way of knowing (absent a special revelation from God) that, in certain Eastern churches, that's precisely the tradition in the liturgy.
No matter what else, though, they certainly loved their only biological Grandson, and perhaps since they've reached heaven, they've continued to love all the others who've been incorporated into the family by becoming members of the Mystical Body of Christ. After all, we call Mary the Mother of God. That makes St. Anne the Grandmother of God, and St. Joachim, the Grandfather of God. We call Mary our Mother. That makes St. Anne and St. Joachim our grandmother and grandfather.
As we celebrate the feast of God's grandparents on July 26, let us ask Mary, Joachim, and Anne to pray for us that we might be good children of God, loving Him and our neighbor with the fire of the Divine Love. Let us love our heavenly family, turning to them with every joy and sorrow, every hope and fear, confident in their loving intercession and the infinite power, wisdom, and compassion of God.