She's got lovely muscle tone, even at that age!
Bet Ozzy loves her, but the poor guy is probably blissfully unaware of exactly how big she's going to get! Same thing happened with our cat, Charcoal - him and Maia used to play happily together but now I see him looking at her and thinking "Jeez! How much stronger is this thing going to get!?". She doesn't realise that she freaks him out a bit now, and still wants to play.
With two dogs it would be different, though- wouldn't surprise me if he doesn't remain the more dominant of the two, despite his size, just becuase he's older.