Not many lady* composers seem to have ventured into the symphonic field. No doubt in times past they were held back by their menfolk. Of those that I know of, I'm going to stick my neck out and claim that Louise Farrenc produced the most impressive output.
*I count all adult members of the opposite sex as ladies, unless they prove themselves to be otherwise!
*I count all adult members of the opposite sex as ladies, unless they prove themselves to be otherwise!