Can't comment on the stable building but my 2 year old has some of the dinosaurs/animals (including a horse) and so far has failed to damage any of them in any way despite throwing them, burying them, using their tails as levers, running them over with assorted cars/trike and making them fight each other.
I used to love Schleich when I was a child, specifically the horses and the accessories to go with them. I had the stables- Its still in my DMs garage. Might be a bit dusty, but it lasted many years of play! I loved it.
Your DD will adore it if she was as obsessed with horses as I was
My DDs had loads of Schleich as kids and never managed to break a single one. The animals themselves are really pretty indestructible, but we also had the plastic stables and I could imagine that getting broken if it were thrown across a room, for example. Schleich also keeps its resale value pretty well, partly due to its robustness.