Genetics or coincidence?

I recently unearthed a wedding picture of my maternal grandmother and grandfather. I am not sure what year they were married but it had to have been around 1900 or a little later. My mother was born in 1910  and she was their third child. What held my interest in the picture wasn't my grandmither's face, although she was very pretty, it was her wedding dress. It was white with a floor length straight skirt, long sleeves, a high neck and a wide sash with a big bow and long streamers hanging down on the front left side. Really very pretty but not particularly unusual for that era. What is interesting, I think, is that 68 years later, never having seen my grandmother's picture or wedding dress, and never having known my mother's mother, who died before I was born, I was maried in a dress that was very similar in style - long skirt, wide sash, long sleeves, etc. She wins though in the tiny waist department. I was fairly slender when I got married, but I know my waist never looked as tiny as hers does in that picture. Still, I think the dress similarities are a lovely coincidence. I think she would have been pleased.