Like it or not, combat is not something that most women relish. Just as gay men gravitate toward flower arrangement, ballet, hairdressing, interior decorating and other "feminine" occupations, lesbians tend to gravitate toward engineering, construction, truck driving and soldiering.
A major problem that women have in the military is getting hit on by men. One good way to repel lustful men is to state that one is a lesbian. That will tend to prevent most men from proceeding further.
If one is prohibited from saying this, then that is not possible.