I think you're stuck teaching a client how to work with a web designer/developer - which isn't fun, especially if this person is both nontechnical and possibly used to working "as she goes."
First, make up your own mind whether you want to help her but charge her for the "brainstorming" time, to come to a final plan; or whether you want to send her away until she has a better idea of what she wants. Then, communicate that to your client. If you decide to continue helping her finalize her plan, explain to her that time brainstorming with her is your professional expertise and time, and in light of that you will need to start charging her for that from this point forward - same as you would for any other client.
Either way you proceed (continue to lead this client by the hand or not), you may want to introduce this client to a couple of ways of working:
- have your client keep a folder of site ideas (like a scrapbook - or, hey, Pinterest) so that she can later look them all over and come to you with a decision, not more new little decisions every week (unless she wants to pay for all of those changes.)
break your larger client projects up into phases, each with their own start/end date and cost. This breaks the work into chunks (for everybody's sanity) and that allows her time to see the site "in action" and make the next set of decisions based on this new-to-her knowledge. Phases for a microbusiness site design might include:
- initial framework with bare-bones responsive code (no design flourishes, just the basic content buckets, minimal back-end functionality)
- first CSS/JavaScript design embellishments: custom colors and layouts, extra functionality (modals, accordions, more complex UI bits)
- additional back-end functionality: a cart, a gallery, whatever add-on functionality the client has decided Would Be Real Neat
(You may also want to set milestones for payment, so that you and she both have an idea of what happens when, financially.)
For future clients, agree to this beforehand:
"Initial 1-hour consult is free, subsequent consults are billed in 30-minute increments. Work begins once you have come to a fixed idea of what you want done, and I write up and then we both sign a Statement of Work. If you have any changes to the Statement of Work, those will count as Change Requests. Each change request will both be an extra charge in addition to the already-agreed-upon work, AND will delay the project completion."