Tauriel watched Legolas climb a tree from afar, a branch broke and the young lord fell into the enchanted river below. Thankfully..
Tauriel did not hesitate to dive in with rope in hand, having tied it to a neighboring tree as soon as Legolas fell.
Swimming to the helpless Prince, the magical properties of the water draining her energy, lulling both prince and guard to sleep. Out of sheer, intense will, the idea of lossing the Prince panged to hard against her heart to allow her rest. Gripping him to her form, she felt herself starting to slip. The tide to strong to swim against, the shore to far, her body and mind to weak.
If it wasn’t for Galion, who saw what was happening and called to the guards to aid the two elves who were on the verge of drowning they would have been swept away.
The guards and Galion himself, pulled on the rope Tauriel held as well and dragged the two from the rushing water.
Tauriel didn’t let go of Legolas until they came ashore and her body fell to the deep sleep that drew her and Legolas in.
Neither one remembered when they awoke. Only faint images remain of the event.
Thranduil watched this happen and began to take notice in Tauriel and her brave reactions.