The same way she survived 100 years without eating or pooping, magic.
The story is serviceable but weak. The fact that almost half of the cast are ghosts weakens the stakes greatly. Contrasting with the sages, the champions get around the same amount of scenes (sans saria and impa), but the group scenes are a let down as they barely interact with each other.
The successors are just there for like an hour.
The towns on the other hand are great, many different NPCs and quests, even the stables have their own thing going on.
The dungeons needed SOMETHING more, maybe making the whole " deactivating them to get in" a whole boss battle in itself would had strengthened the experience. But I guess they had to do the "shoot the eye/glowing spot" thing somewhere.
When they did it good was with the guardians, now that I'm with my ninja super onesie of like 40 defense I can shrug like 6 lasers, but managing to learn how to fight and win against the guardians (and the lynels) little by little was what made me feel like a badass in the game, from a panicked shriek, to cutting its legs and running for the tower, to crippling them and then smack until victory, to just shooting them in the eye (turns out if you don't make the eyes super big, it is actually cool to shoot them!), to just deflecting the beams, to whatever crazy thing I can do later, they were pretty effective as enemies.
The blights were cool in the first Ganon battle (when I didn't do the dungeons) as I freaked out thinking that I was killing/releasing the corrupted souls of my friends, finding out later that Ganon just beat them with slightly stronger versions of themselves was disappointing.