She is a very capable black woman?
Why do you need to repeat the gender twice? Why do you need to mention her race?
How about --
She is a very capable person.
The use of descriptors such as "black" and "woman" in the sentence might be included to emphasize or acknowledge the intersectionality of her identity and experiences. It is important to recognize and celebrate diverse backgrounds, as historically marginalized groups face unique challenges and barriers. By explicitly mentioning her race and gender, it highlights her accomplishments in overcoming those obstacles.
However, it is also valid to use a more simplified and generic descriptor like "person" to focus solely on her capabilities and skills without mentioning race or gender. This can help promote a more inclusive and unbiased perspective. Ultimately, the choice of wording may depend on the context and the intentions of the speaker or writer.