Coldspring, Texas (Zone 8b) Plant, watch and learn. My orchard
If the tree is still young, I would wait to cut those two lower branches. Those leaves are helping it grow. Many olive growers do t prune at all until year 5 to allow for maximum photosynthesis for young trees. Even water sprouts are kept when young. It is wonderful that you were able to save a piece of your grandmother's tree. How precious! Let the baby grow up then take cuttings as you do your first pruning later.