Emily does not seem to be 1/32nd scale, it would have to be 18" long and it is 16". Any info on that?
It's likely she wasn't made to scale as a real Single because the primary intention was to catch the character Emily and how she looks in the show.
Her body is still good for a cheap kit-bash if you want a quick, cheap Stirling Single, as long as you don't mind the Thomas engines not being completely to scale.
Emily is "Thomas and Friends" scale. In other words her size is dictated by the art used to create the show - not prototype locomotives.
Actually, Bachmann have been rather clever. Rather than compromise and make Thomas & co a range of 1/32 (Gauge 1) models, they've scaled them to the large scale range and they're roughly 1/24. All you really have to do is regauge them and they're exactly to scale.
Just purchased Emily & some wagons for that exact purpose, spoke to a few people who have been working to G64 (Standard Gauge G scale) and they've commented that the Bachmann Thomas range is a godsend.
See some example conversions here: http://www.forum.gscalecentral.net/G64-Troublesome-Truck-Conversion-m122589-p6.aspx
Jack