Fangirl

Kate Stewart described Osgood's behaviour as "fangirling" when she noticed that Osgood had chosen to wear a long, multi-coloured scarf for her first encounter with the Doctor in Trafalgar Square. At some point, someone had added "fangirl" to the list of qualifications in Osgood's personal file at UNIT. (PROSE: The Day of the Doctor)

The Eleventh Doctor complimented her on the scarf, but Kate felt that this was not the time for it. (PROSE: The Day of the Doctor) Osgood had previously donned a version of the Third Doctor's green velvet jacket and frilly shirt on a mission with Jo Jones, (AUDIO: Tidal Wave) and would later update her wardrobe to include a bow tie, in the style of the Eleventh Doctor, on meeting the Twelfth Doctor. (TV: Death in Heaven)

Osgood characterised herself as a "big fan" of the Doctor, (TV: The Zygon Inversion) and she eagerly read all files available to her at UNIT on the Doctor and their travelling companions. (AUDIO: Tidal Wave) Osgood placed immense trust in the Doctor, praying that he would save her, (TV: The Day of the Doctor, The Zygon Invasion) and idealised Jo Jones. (AUDIO: Tidal Wave) On first meeting the Eleventh Doctor, Osgood was so excited she had to be reminded to use her inhaler. When the Doctor asked for her help analysing some stone dust, she could hardly formulate a sentence in response, simply repeating "Yes" as her asthma kicked in again. (TV: The Day of the Doctor, PROSE: The Day of the Doctor)