Um, I believe that would be Aloïse Buckley Heath. (At first I did a double-take. Then I began to wonder if "Alois" is only the latest in a long line of originally masculine given names to be commandered for female use.) And this may be the column you had in mind. I suppose it's appropriate to appropriate Sullivanesque usage and call this the "money quote":

I really didn't see how the Christkindl custom could go wrong, though. I still don't. In the Trapp family, at the beginning of Advent, everyone writes his name on a piece of paper and the papers are put in a basket, which is passed around as soon as the children have finished singing "Ye heavens, dew drop from above." Everybody picks a name from the basket, and the pickee, if you follow me, becomes the picker's secret Christkindl, and the idea is, you do your Christkindl a good turn every day until Christmas without letting him know who you are. It sounds simple, spiritual, and also fun, doesn't it? And it works out beautifully in the Trapp family. In fact, through Advent until Christmas, the Trapp household resounds with the glad cries of Christkindlen[*] who have found their shoes shined, their dollhouses tidied up, or the table already set the day it was their turn.

Apparently, the reference is found in Around the year with the Trapp Family (New York, 1955) and so, presumably, represents a genuine Austrian custom. Good work, luckymarty!

[*] Obligatory grammar nitpick: Christkindl is a Bavaric diminutive of Christkind, equivalent to Standard German Christkindlein. As even snowy_owlet can tell you, it is invariable in the plural. One Christkindl, two Christkindl. There's a certain charm to swiping the English irregular plural -en from children and slapping it on a German word, so I forgive Ms Buckley Heath entirely her bit of poetic license.