Emily is an emerald green engine.
- 2011 (CG style face)
- 2013 (updated face, added detail, curved edges and longer magnet guards)
- 2017 (redesigned face, slightly redesigned details, smaller middle wheel, more compact tender wheels)
- 2018 (printed details on exposed wood, smaller face and smokebox, larger all black funnel, larger cab, flat rectangular tender)
- 2019 (printed details on painted wood, metal pins in chassis)
- The prototype 2004 Emily did not feature her chocolate-colored running boards.
- The 2009 Yearbook incorrectly describes her as rescuing Oliver and Toad from mud.
- One prototype 2013 Emily has been seen with and without a red front bufferbeam.
- The 2017 prototype Emily shows her with a 2011 styled face, her running broad is now included on her wheel arch, her "grate"/"fence" on her tender is missing, the one box closest to her face looks more squished and she has an incorrect black roof.
- The 2018 Emily has her running board printed on unlike her prototype.