Jamie Lynn Spears (35) is on the verge of an emotional milestone: her daughter Maddie Briann Aldridge (17) is about to finish high school – and the singer can hardly hide her feelings. On Instagram, Jamie Lynn now shared touching insights into the preparations for the graduation ceremony. "Already emotionally hit, the actual graduation ceremony has not yet taken place," she wrote on a contribution. Among other things, it can be seen how Maddie i…