Homemade Skirt

I believe my mother made this skirt in the 80s with a serger. Looking at the stitching, the original buttons, the fact that there is no sign there ever was a manufacturer label or care information, and other garments I have that she made, I'm about 80% sure it was something she made from a pattern. Unfortunately it doesn't fit me or I'd definitely keep it. The waist measures 27 inches, making it a small. Some of the original buttons were mismatched so I replaced them with matching buttons.