The 19-year-old forward - who spent two years with Durham before joining City a year ago - arrives after spending the first half of the campaign on loan at Crystal Palace in the Barclays Women's Super League.
She joins versatile defender Charlotte Wardlaw, who joined the Magpies permanently last week, as the latest additions to Becky Langley's squad as they look to mount a challenge for a third successive promotion.
Harriet Massey brought newcastleunited.com this gallery as Pritchard - who could make her debut in Sunday's Barclays Women's Championship clash with Sheffield United at Bramall Lane - took a look around her new home after checking in at St. James' Park.