Why Is It Customary To Write ale'ah hashalom for a Woman and Not z"l

Shalom rav,

In truth, one may write alav hashalom for a man as well, and one may write z"l for a woman as well (see Rema, Yoreh Deah, siman 344, seif 9; Kitzur Shulchan Aruch, siman 143, seif 8; and Nitei Gavriel, Aveilut, vol. 2, chapter 63, note 19). However, it is indeed the custom, in most cases, to write z"l for a man and ale'ah hashalom for a woman. I did not find anyone who wrote a reason for this.

Good tidings,

Hillel Meirs