Well Sue answered my question about the mystery fern that appeared in my garden!
It's called "Sensitive Fern" and Sue even shared a video about it here.
Then I began to think about the fact that this is a fern normally found in wetlands. I think that the wildlife brought spores into my garden. I'm almost sure it was the foxes that frequent our backyard because they have a larger range of territory than the smaller animals and we live about 2-3 blocks from two different waterways in our parks.
Sue did more digging and found that the plants is referred to as "sensitive" because of its intolerance to cold...the plants die back with the first frost!
I also wondered about quilt patterns that used the word "ferns" in their title. Only found one from 1940, an Alice Brooks pattern:
That was a bit disappointing since it didn't look like ferns to me at all. I think Jocelyn has the right idea. She said she picked ferns to use as an applique template.
Thanks Sue for sharing your sleuthing skills with us!
Have a safe and happy day!