Jovian (aka J'rim) was exactly what Robin wants in a brother; laughing, friendly, passionate and lively.  Robin's interactions with J'rim ranged from the excruciatingly frustrating to the overwhelmingly wonderful, exactly the way she'd have it.  Robin is equally delighted with all of J'rim's friends, the flying and the walking alike, finding them to be kindred spirits of the air and the short life lived to its best.

And even though, the change in her own parentage would make Jovian a cousin rather than a brother, she still considered the Bronze Dragonrider a *brother* and one of her closest confidants in Amber. 

That is, until she was present at the death of soul-bonded, the great bronze dragon Canareth.  Robin held her brother and watched as his sanity leaked away,  In the end, all she could do was send him away.

Now, combined with her own grief over the loss of Canareth, is the cold knowledge that no matter how resilient her beloved hero-brother is, he will never be in her prescence again without being reminded of the worse possible day of his life.