In my quest to pinpoint the location of the attack on Ada Wilson, I was referred to Old-Maps.co.uk, where I found several maps of the area covering the late 19th and early 20th centuries by searching for Wentworth Mews. A couple of the maps depict the housing along the stretch of Maidman Street which has been covered over by Mile End Park, and the clearest of these is the one from 1920.
Based on this map (above), plus an account of the attack on Ada Wilson and census records, I believe that I've been able to identify the location where Ada Wilson was attacked. It appears that all of the dwellings on Maidman Street at the time of the attack were along the stretch which is now covered over by Mile End Park. There apparently were no dwellings with Maidman addresses along the stretch of Maidman to the east of Burdett. So, as far as the 1891 census of the area was concerned, that stretch of Maidman didn't exist.
The census indicates a total of 33 dwellings along Maidman, and the map indicates 11 small dwellings and 10 large ones. The account of the attack contained in an article entitled Extraordinary Outrage at Bow: Attack on a Dressmaker from the March 31st edition of The Eastern Post & City Chronicle sheds light on the configuration of these dwellings. In it, Rose Bierman is reported as having stated that "Mrs. Wilson lives in the front room, her bedroom being just at the back, adjoining the parlour. My mother and I occupy two rooms upstairs." Reading between the lines, I've concluded that the small units shown on the map have two stories, and the large ones have one. This yields a total of 32 dwellings, so I can't account for one of the dwellings indicated in the census, but it's probably not significant.
Some accounts refer to the attack-site as 9 Maidman, and others as 19 Maidman, indicating that 9 is the bottom floor and 19 the top. So, I assume that Ada Wilson's place would have been the third from the right in this row of apartments.
The closest landmark which I assume have remained unchanged since 1920, when the reference map was made, is the center of the intersection of Maidman/Wentworth Mews and Eric Street. (By the way, Eric used to be Erie, and you can probably surmise the reason for the change.) I also needed a reference distance, and I chose the distance between the centers of Eric and Maplin. I then determined the ratio of the distance between the aforementioned intersection and 9 Maidman, on the one hand, and the distance between the centers of Eric and Maplin on the other. This ratio is 1.52.
I also measured the angle between this intersection and 9 Maplin, and obtained 11.36 degrees below due west.
Next, I measured the distance between the centers of Eric and Maplin in Google Maps, multiplied this by 1.52, and thus obtained the distance between the center of the reference intersection and the location of the former 9 Maidman Street. I then used MB Ruler to plot this vector on Google Maps, right-clicked on the spot, and thus obtained the coordinates for the former 9 Maidman Street: 51.524422,-0.035126.