There is no question that an Ashkenazi woman can pray maariv if she desires.
It has optional status according to many, R Melamed for instance writes
Women never took Maariv upon themselves. Therefore, Maariv
retains the status of an optional prayer for women.
Since a woman needs to pray once a day at least, he later writes that
If a woman was unable to pray both Shacharit and Mincha she should
nonetheless pray Maariv.
R Doniel Neustadt writes here
Note that all tefilos in which women may be exempt, such as the daily
Ma'ariv [...] are still permitted to be davened by women. [However one
should ask a rav for sefardic women] since some Sephardic poksim
(e.g., Yechaveh Da'as 1:68; 3:3) rule that women are not allowed to
daven certain parts of the davening from which they are exempt.
According to R Yosef Ber Soloveichik, maariv has obligatory status for women.
See also here for more sources.