LoveElsie as a nn. It would be great to see it make a comeback. Though I love Elsa, too. I wouldn't be surprised if Elsie made a comeback following the drop-a-letter trend of Mikayla-Kayla-Ayla/Madison-Addison. The leap from Kelsie to Elsie isn't very big.
My grandmother was Elsie and her mother was MaryKelly, so I thought it would be "so kewt" (about 15 years ago, mind you) to have a little girl and call her Kelsie. I find Elsie MUCH nicer than Kelsie now, though. ;)