My great-grandparents, John and Claire, were married in the early 1940s and stayed together until his death three years ago. Since then, my mom and her cousin both wore Nana's dress in their own weddings and it's as beautiful today as it was then.
This is my grandparents at their wedding in the early 50s. My grandma was almost 4 months pregnant but still managed to fit into this teensy outfit! The were married until she passed away unexpectedly in 2008. They spend fifty five years together, bickering, laughing and generally being amazing.
Looks like it was more of a tiny squeeze for your petite grandmother to fit in that lovely suit. Beautiful at a turning point in a beautiful relationship!