I added this same description to the Golden Book Edition page for this book.

I had this book as a child around 1953 and 1954. It was in a picture book format about 10" x 12" and a 1/4" thick. I have looked for it for years.

As an adult, I realized the story took the kitten through the seasons of the year looking for her lost pussywillows. All I remembered from it as a child, was the closing line: "Anything you lose is always where you find it."

She had been a kitten who fell asleep playing underneath some pussywillow branches in bloom. When she awoke they were gone, and she went looking for them. The pictures and story took her through summer, fall, and winter, until she fell asleep from exhaustion. By this time it was spring, and when she awoke, she was underneath the blooming pussywillow branches.

At least that's the way I remember it.