Jamie Lynn Spears is celebrating a milestone moment for daughter Maddie. Spears, 33, shared a carousel of photos via Instagram on Sunday, March 30, featuring Maddie, 16, in a floor-length lilac Sherri Hill dress with a thigh-high split. Maddie paired the look with metallic Christian Louboutin heels, styling her hair in a half-up, half-down ‘do….