My thoughts, the Unskinnyboppy one is a perfect rendition for sewing. Make the bookcase part with adjustable shelves, she has no idea what she will need to put here. The plywood top will be ok if you use a quality plywood that you can finish to be smooth. Why not start with a second hand table to finalize what will work best for her?Unskinny Boppy got her "craft" table from a Pier 1 closeout sale. Take a trip to the Ikea store in Charlotte and look at their cubby storage/bookcase ideas and dimensions.
https://unskinnyboppy.com/2012/04/recreating-pottery-barn-style-without-2/
This WIP sequence of pics looks similar to what you want to put together without the start to finish carpentry/woodworking. Here's a 6 unit cubby that's 30" h x 44" w, but there are other sizes available as well.
https://www.pinterest.com/pin/48906345933406655
https://www.wayfair.com/furniture/p...rage-30-cube-unit-bookcase-clop1226.html?piid[0]=21979228&piid=21979228
Put a plywood work surface across the top(s) and your wife will be ready to sew. :eusa_clap