What do you think about a Female Attorney Niche

I sm an attorney with 28 years of litigation experience. I want to develope a niche for coaching women lawyers who feel they no longer want to practice law. I believe they want to practice law, but do not enjoy the way this male dominated profession practices it. So i am trying to think how to create this niche.

A circumstance that is generating doubt for me is that I turned 68 in June of 2018 and this creates thoughts that i don’t have time to create a successful ($500,000 or more) coaching business. Do you have any statistics on the average time it takes to create a coaching business that generates $200,000 of gross income a year,? Same question for $500,000 or more in gross revenue.