From their interactions so far, I like to see Ditto kind of like her grumpy uncle/aunt.
She’s not entirely on-board with putting up with her, but sees Inkie as too cute and fragile not to take care of her.
Also they’re both pegasi with white coats and blonde manes, so they could, in theory, be related.
If this is how inkie-heart herself thinks of it, I can’t say.