I have a few.
Almost all of them are cotton. Some are new and some are very, very old. I was wearing the one pictured at left while pregnant with Katie. That's 21 years ago -- I don't know what that translates to in nightgown years. It's a soft, old faithful, and I still wear it.
Apparently, I favor long and white, buttons and ruffles. There are a few florals, some blue, a shocking pink! Most of them are missing the tags because I have an annoyance with those irritating things that seems to only get worse. Many of the sleeves are whacked off because I can't stand anything too tight around my wrists. If it was easily accomplished, I simply removed the elastic, but most of the time, it required a whack job to make the thing wearable.
I often spend a good deal of my day off or a Sunday morning in my nightgown. Having no neighbors on the east side, none in back, and mostly hidden from view in the front, I can have coffee on the patio in my nightie or hang out the wash or pull weeds or water my tomatoes.
I suffer comparison to pioneer prairie girls gladly. ; )