Q. A woman who always davens Mincha forgot to say 'Vessen Tal Umatar Libracha' (give us rain and dew) on the first day of the change and adding of this prayer. Does she have to repeat the Amida as men do? If she didn't remember until that night and she usually does not daven Maariv, what should she do?
A. Women who daven Mincha, although not obliged to do so, if they constantly do so, they will have to repeat the Amida if they did not recite Vessen Tal Umatar Libracha, the same as men do (Daas Torah 114: 5).
If the time for Mincha is over, she will have to daven Maariv twice, even if she normally does not recite Maariv at all.
The first Shemone Ezre is a regular one. The second one is a Tashlumim or repayment for the proper Mincha missed.
(See Mishna Berura 263: 43) for a similar ruling.
Horav Shlomo Miller's Shlit'a opinion is similar.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit'a