Link's stark difference to the other Kokiri is what first made Saria notice him.
He had always looked different, no matter what Kokiri garments he wore. No one knew his parents, he lived on his own and was in the care of the Great Deku Tree. As all the Kokiri children grew older, each one found their own fairy. Link never found his fairy and eventually had to be given one by the Great Deku Tree. The others shunned him because of this, because of his difference, Mido in particular.
Saria, known for being one of the kindest Kokiri, never judged Link, never excluded him from her life. The more he was repelled, the closer she brought him to her. Before she knew it, Saria was in love with him. She never even cared to catch herself falling for him.
Saria enjoyed the times when they were alone, away from all the other Kokiri. She could never have him over to her small house anymore because of the boys that watched her so carefully. Saria only wanted peace for the forest and acceptance for Link, so house calls quickly became a thing of the past.
During these times alone, Saria taught Link to navigate the Lost Woods. She showed him all the hidden paths, underground tunnels, and cool fields. Saria came alive in the woods and being with Link only made this time better. She achieved a happiness here that she couldn't find anywhere else.
Link and the woods.
This was all that she needed.
When Link was summoned before the Great Deku Tree and was told his destiny, Saria felt more grief and more pain than she ever had in her short life. Link was leaving, the Great Deku Tree was dead, and she felt a darkness creeping in on the forest from the outside world; an invasion of evil.
She could hardly bare it. So Saria waited for him, waited for him at the exit of the forest. Little did she know that her patience would be tested with this boy, for she had more waiting to come.
When he began rushing towards the tunnel that would lead him to his inescapable fate, she called out. Saria had one last gift to give this small boy in green before he faced the dangers ahead.
A fairy ocarina.
Link was grateful, and the last moment they shared together as children came to be one of the most painful in her memory. There were so many things she could have said to keep Link safely nestled in the forest, together with her. But she knew it was wrong to tempt fate, especially when the whole of Hyrule was involved.
His steps began slowly, hesitantly, but quickly turned into the hurried run that she had come to love. He disappeared from her sight and tears burned in Saria's eyes. Her fairy fluttered around her trying to be of some comfort.
Link came back a few times, and those were times when Saria was most happy. He never stayed for long, always rushing off somewhere. He was always preoccupied, which was understandable.
She always tried to push away those light, nagging thoughts that told her that part of his mind always dwelled on the fair Princess Zelda.
Who knew such light thoughts could weigh so heavily upon her mind.