Q. I heard that women are not allowed to work on Rosh Chodesh. I work as a secretary and can't just miss those many days during the year or I will loose my job. I also haven't seen other very frum women refraining from work on Rosh Chodesh. What is the correct thing to do?
A. Shulchan Aruch (O.H. 417: 1) writes that it is a good minhag for women to avoid doing work on Rosh Chodesh. Rema (ibid) maintains, that if their tradition is just not to do some work, they should follow their tradition.
Mishna Berura (3) quotes as a source, the fact that they were rewarded for refusing to contribute their jewelry for the making of the eigel.
Biur Halocho (ibid.) is quite stringent in having women keep the tradition, at least by partially refraining from doing some work, so it would be recognizable that this Rosh Chodesh day is special and different.
Horav Shlomo Miller's Shlit'a opinion is that she should definitely try to do some significant change on the work she does on that day.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller, Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit'a