She has a good command of the English language.
The second sentence is grammatically incorrect. It appears to be missing a verb and some words to make sense. Here are some possible corrections:
* "When speaking to her troops, she is overbearing." (This implies she is commanding and domineering.)
* "When speaking in front of her troops, she is very confident." (This suggests she is a strong leader.)
* "When she speaks to her troops, she gets her point across effectively." (This focuses on her communication skills.)
It's important to understand the intended meaning to correctly revise the sentence.