Effie was bouncing in the light, waiting for Damon (and Bonnie, but mostly Damon). He didn't know her, not really...he knew who she had been, the troubled, violent sociopathic slut who had come to Mystic Falls to escape her father. Damon had been a drinking buddy and sex partner, but he had better things to do than keep track of a trouble redhead...which is probably why he hadn't noticed she had died.
...and in death, she found piece, her mind fixing itself back together, returning her to the girl she once was. So while she knew a lot about him...he knew so very little about her.
But it didn't matter, because he was here now and free.
Once the light settled down, and Damon crossed over, Effie took a running leap, wrapping her arms and legs around him, pressing her lips against his.