As another attorney stated, buy as much coverage as you can reasonably afford including the most UM/UIM coverage available. I personally think that the UM/UIM coverage is the most important part of your insurance package because is gives you something to pursue if you are hit and injured by an uninsured or underinsured driver. Here in CA the percentage of uninsured or underinsured drivers out there is huge.
Yes, you can go to the police and report the incident. Yes, you can go after her regarding the deductible though the cost to do so may exceed the amount of the deductible. Your insurance company should be able to provide you with some assistance unless you've waited too long.
I would not tell the other carrier what your UM/UIM limits are. Has that carrier told you what its insured's policy limits are? I doubt it. Regardless of who the carrier is here you are not "in good hands." I am in San Jose if you want to talk. There are a lot of us PI attorneys. Find one you feel comfortable with and let that attorney help you.
I am not aware of a requirement but it is certainly the best practice to put up some kind of warning signs if the floor people are using is going to be wet. I am working on a similar case in San Jose right now. A gym floor at a 24 Hour Fitness Club locaton was mopped and a guest fell a fractured an ankle. There were "cones" up but so far from where the floor was wet that they were not at all effective in warning of a slippery condition. Feel free to call is you'd like a no-charge consultation....
I am very sorry to hear of your loss. Whether it is the result of negligence or not is not something any attorney on Avvo can tell you. You need to contact an attorney here in the Bay Area who does medical malpractice cases and get some guidance. I suggest Brad Corsiglia or Jeff Janoff. Both are in San Jose and will know my name. Call and set up a time to speak to either or both of them.
You're right, nobody has suggested a number. I will. If you have a TBI with confirmed cognitive deficits and tinnitus it's a 500k claim or more. Doubt that will be offered. Do you even know how coverage the at-fault driver had at the time of the crash? Probably not. Contact me if you want plain talk.
Contact your homeowners insurance agent to report the matter. It will get to a claims person who can help you get a file opened. If you get sued the insurance carrier secure legal counsel to defend you. Accidents happen. It is a shame that schoolyard mishaps leads to lawsuits.