I looked at my lists and did not find a Hannah Sovereigns/Soverns/Severns.....I know that Turney was often spelled as Thurny, Turnni, Dorney, Durney, etc. because it was German and they way they pronounced it.
I did find one you might want to look at.
List C Inclosed in Bouquet to Gage, November 30, 1764, Gage Papers, Clements Library, University of Michigan List of Necessaries furnished to the Captives of Pennsilvania Fort Pitt. Nov ye 30th 1764 Names - Female 16.Hannah Maria Sourbach1 Shirt, 1 legging, 1 shoe Pak
Fort PittDec ye 1t 1764 Received of Colonel Bouquet the above mentioned eighty one Captives and the Neccessaries as against their Names respectively, being in the whole fifty three shirts, forty nine pair of Leggings, sixty three pair of shoe packs, and thirty nine blankets. Asher Clayton Lt Co 2d B Pa Regt. Indorsed: Colonel Clayton's Receipt for Eighty One Captives, & their Necessaries, sent down from Fort Pitt to the Inhabitants----- December the 1 1764
Sourbach is far from Soverns.......but could it be possible?