This is actually my very own daughter at six months old. I never took taking photos of family very seriously until I had her. "They grow up so fast" is probably the most common thing heard about children, but I've found it to be surprisingly true. Documenting her at each stage of life is so valuable to me.
I wanted to find an outdoor place that didn't have many distractions so she could be the clear star of the photo. This specific shot had a very long background that would give me a very beautiful blurry background, and I accentuated that by choosing to use my Canon 135mm f/2 lens.
Mom was right next to the baby in case of a fall. From there it was as simple as letting her be herself!
Canon 5dmk IV
Canon 135 f/2