Here’s the best I could do to come up with some realistic numbers. First, I printed the picture out. Second, I took various measurements across the width of the walleye to find centerline points in order to measure the length of the fish down it’s centerline. Keep in mind the tail goes off the end of the picture, so what I did was drew a line from just off the end of the tail on the bottom side long enough to cross the centerline of the fish. This line was drawn perpendicular to the bottom edge of the tail assuming that if the tail was squeezed together, the top edge and bottom edge of the tail would run nearly parallel to each other thus giving the “squeezed tail” effect. I also left a tiny bit of sluff room when I drew the line off the end of the tail in order to compute a more conservative measurement.
And so, I measured the centerline length of the fish using an engineer’s scale and came up with 38 units. I then measured the width of the gal’s fingers across the centerline of the fish and came up with 3.6 units. I then measured the width of my own 4 fingers at the same location in which the centerline of the fish crosses the gal’s fingers and came up with 3.0-inches. Calculating through…..38/3.6×3.0 I get a total approximate length of 31.67-inches. Now in many cases, a woman of her size is likely going to have fingers smaller than a man’s. So if hers measure 2.9-inches across, then the fish is 30.6-inches and for every 0.1-inch her fingers are less than mine, the walleye would be about 1.05-inches shorter.
I have no clue of the width of her fingers, but even if they equaled the width of my own (located just above the middle knuckles), the fish would still be well under 37″. In fact, the width of her 4 fingers would have to be 3.5-inches across in order for the calculation to equal 37-inches. Those would be some big woman hands! 
While I don’t believe at all that this fish is near 37-inches, I do want to say congrats to the gal on a very nice fish! More than likely, that fish is in the range from 29″ – 31″ and at those lengths, the weight of 12lbs becomes much more feasible. Excellent fish!
