The question was asked where is the source for the Rashba (3 posts above) and it was given (2 posts above). Argue, if you must with Rabbi Jack Abramowitz about Rashba if you wish. We know who will prevail.
Written so eloguently by Rav Ellison in “HaTzneah Lechet”, page 192 note 138 is the following:
The poskim do not allow women to wear trousers.