If you work with the right resources, you may learn what is motivating your wife to delay. I have had these situations come up in my mediations. I have found that therapist/coaches are invaluable here. You do need to make sure that your legal interests are not being jeopardized or harmed. So I agree that you should speak to an attorney who can represent you individually (not a neutral). If that attorney understands and appreciates your the reasons you entered into mediation to begin with, s/he will likely agree to communicate with the mediator and/or coach to work on how best to bring a sense of safety and value to your spouse and, if all goes well, bring her back into the process for completion.
Often what happens is that the divorce suddenly becomes real and one spouse is not ready (emotionally) to disengage. It could also be that the "voices" around her, while well-meaning, are undermining the work that has been done thus far. Forcing someone in that situation to do something they are not ready to do rarely ends well - in fact, in one such case, it resulted in the non-moving spouse to hire a shark litigator attorney who cause the costs of the divorce to increase exponentially; most of which, husband had to pay.
I'm not suggesting that you do nothing. I don't know your situation well enough to advise you at all. There are a great many peacemaker attorneys in San Francisco AND some wonderful therapist coaches. Do your research. Talk to your mediator. The process clearly has to be modified. But modify it in a way that puts you in the best position to achieve success as YOU have defined it; not as someone else defines it.
I hope this is helpful to you. If you have other questions, AVVO is a wonderful resource, and you have many more in your area, I'm sure. Just don't lose focus of the big picture.
The best thing you can do at this point is retain your own attorney to advise you. If your wife won't cooperate, a mediator or neutral attorney, who is not representing either of you, is a waste of money. Those kinds of options only work when the parties are willing to work together cooperatively. Your own attorney can help you prepare your paperwork, and get the case moving.
If you elect not to retain your own attorney (which I don't recommend), you'll have to do the rest of the process yourself, without your spouse's cooperation. Prepare and serve your Declaration of Disclosure. File your Declaration re Service of Declaration of Disclosure (Form FL-141). If you need documents or other information from your spouse, you may have to resort to formal discovery, and file a motion to compel if she doesn't respond. When you have everything you need, file an At Issue Memorandum to let the Court know you are ready to proceed. This gets the ball rolling to complete the case. The Court will set a settlement conference date, and both of you will be required to be present. If the case doesn't settle, a trial date will be set.
I do not represent the person who asked this question, and was not given enough information to provide a better answer. The limited information is enough to indicate that a consultation with an attorney in your area is necessary and advised.