Obvious points of employments could be guards. Yes, relatively small units - but precisely for that reason, the employer can select the minority of relatively tall and strong women (who, in any case, are bad-looking and have relatively poor marriage prospects compared to the weaker and prettier ones) - and armed and trained women can appropriately guard spots which otherwise would be tricky for matters of decency. Like a palace with a large number of concubines of the ruler (Turkey, anywhere in India, Thailand, China, Japan...), or a palace of a female ruler or regent (in 18th century, including Queen Anne, Empress Maria Theresia, Empresses of Russia).
Or showing up on a battlefield when their employer (male or female) chooses to lead from the front.
Or possibly taking police duties in capitals, which would enable them to enter homes and apprehend and search women without accusations of impropriety. They may have problems with big strong male criminals, but remember that e. g. Janissaries patrolling the streets of Istanbul were limited to clubs - not allowed blades or firearms to restrict savagery.
Considering how a Prussian king was able to select unusually tall males for his guard. If Catherine II wanted to select unusually tall women for her Guards so that she could really fight along them on a battlefield, how big unit could she have that realistically could fight average sized men on equal basis?