Fiona’s aunt had a parrot as a familiar, which could bring her gossip from the village.
Her mother had the traditional black cat, and always said that traditions were important.
Her cousin, who lived in a city, had a pigeon familiar. (Fiona’s mother had scoffed at the idea, but it was amazing at delivering messages.)
But Fiona had chosen a raven. It could fetch her gossip (even if it was forest gossip), it could deliver mail (even if it got distracted), and there was even tradition behind it.
But mainly she choose it because of its ability to foresee deaths.