If you are still looking for information on Rev William Steven's wife, look at 'A Brother's Portrait: or Memoirs of the late Rev. William Barber'. Wesleyan missionary to the Spaniards at Gibraltar, 1828. Available on-line.
William was my gr gr grandfather's brother. Aquila Barber wrote the book in 1830.
William's early life was in Bristol and it seems Mrs Steven's had considerable influence in his decision in becoming a minister. Look at page 3 where there is reference to her.