Thank you so much. I hope it does!!!
It seems to me that since you have your own business this is exactly what could be able to answer the question and show your entrepreneurial mindset. Although showing strong innovative or entrepreneurial spirit is not only building a business, if you do have a business on the side like you, it perfectly shows these values and it is impressive indeed.
The way I would structure the answer is by showing how you came up with the idea in the first place, how you approached the strategy stage of your idea and finally how you used innovative thinking to build something different in your business which also differentiates you and your business from the competitors in the market (if any).
I would also link these innovative thinking skills developed through building your own business with becoming a successful lawyer at the firm since you will be able to display this skillset and make the most of it in the role (this could be one sentence only at the end of the answer).
Good luck with the application and congratulations for building your own business, this is super impressive and I am sure it will impress the graduate recruitment too!