The Spanish word 'sobrina' meaning 'niece' comes from the Latin word 'sobrinus' which meant 'cousin'. Over time, as the word evolved from Latin to Spanish, its meaning shifted from referring to a cousin to specifically denoting a niece - a daughter of one's sibling.

A closely related Spanish word is 'sobrino', which means 'nephew'. Both 'sobrina' and 'sobrino' share the same Latin root 'sobrinus', with the -a/-o endings distinguishing between feminine and masculine forms in modern Spanish.

While English doesn't have any common words directly related to 'sobrina', it's interesting to note that English borrowed the French word 'cousin' (which comes from the Latin 'consobrinus', meaning specifically 'mother's sister's child'). 'Consobrinus' is actually related to 'sobrinus', both sharing the idea of family relationships.