What I am about to type now is the last few paragraphs of the book, Lovers Leap, by Lisa Tuttle.
The last line just got to me.  I guess I'm a romance freak.  But this romance was cute and romantic in a kinda morbid way. But whatever, enjoy...

"Jenna," he breathed.
As soon as she saw him she was transformed.
It was as if she melted.  Her taut fingers released the rocks that tumbled, disregarded, to the ground. A soft smile curved her lips and lit her eyes.
"Darling," she cried, and began to run.
Dave stepped forward, his arms opening to catch her.
I think it was meant to be a lovers reunion, a happy ending to this miserable day. And so it might have been if they'd been in a meadow somewhere, standing level, and not on a slippery, narrow ledge jutting out of the side of the mountain.
Had Jenna forgotten where she was, or were her last actions deliberate? She came running at top speed and then threw herself at Dave.
The full weight of her body knocked him off balance.  He staggered.  He might have recovered, but she didn't give him the chance.  She didn't let go or draw back.  She went on, pushing him, throwing herself at him until he went over the edge.
I think she was kissing him as they fell, locked in their final embrace, to their deaths.

- from Lovers Leap, by Lisa Tuttle