I am currently working for a accounting firm. I have my AS Degree in accounting and working on my Bachelor in Accounting.?

You want to be an accountant.

Almost everyone in your shoes dreams of opening their own firm at some point.

Some will

Some will change their mind

And some will end up with the perfect situation = your boss will be interested in passing the reigns when you are ready and you will buy the practice.

Your boss already knows this....

You don't even have your degree yet. Your boss knows that you are not likely to stay more than a year or few years....

Don't worry about it now, you are a long way from being qualified to start your own business. There is more to running an accounting firm than the math and forms.

Tell her that only if you want to lose your job. Why would she keep you on, invest in your career development, and expose you to her business when she knows you're planning to leave and take business away from her? You have no idea what the future holds. Keep on learning (both in school and on the job) and see where things go. When you have a solid plan to leave, with an end date, then you tell her you're leaving. Not before.

you may have the plans in your head but you are also now planning to get more education, your plans are a long way down the road and there is no assurance you will ever put them into play

you have told her you would help her build her business, that appears to be your current priority now that you have expressed it

Since you are stilll in school it will take years before you will build up a following big enough to cause her any real competition.

You don't.