The text of the bill can be found here.
First, no bill or amendment is ever perfect and neither is this one but I support it.
I would have felt better if it was defined as a Transsexual Rights addendum to the original bill but that will never happen in a liberal state like California. Personally I have no issues with any laws that help kids in K-12 that are transsexual or transgender/transvestite. I will tell you why after I discuss my few reservations on the bill.
Personally I believe a provision should require the student be under the care of a doctor but having said that I find it difficult to believe the parent(s) of any student in K-12 would let their child transition, which should be added also, and then submit the child to that crap without a medical exam and access to a therapist. The simple fact it restricts this access to areas designated female to students limits the probability of any transgressions. Transgressions are possible but highly unlikely since kids are decidedly different than adults. I do understand the concerns of some but since the child must have a gender identity condition and this must be public it means they must have transitioned. If they have transitioned in school they have more courage than you can possibly imagine and nobody is going to transition on a lark.
I am ambivalent about the ability of trans kids to play for the sports team of their new gender identity even though I believe they should be on blockers, at a minimum, when they reach high school. I just do not see this as an issue since the individual will have to be transitioned and if they have transitioned they are more interested in being accepted as girls or boys than making waves or calling undo attention to themselves is counterproductive. Could it happen? Yes, but it has not in many school districts where this has been the local rule for some time. I believe if it happens then the situation may need review but I just do not see it being an issue.
Along with protecting transsexual and transgender children this bill helps them be who they are. I have little fear that a male will transition and go through that hassle and then have to stay transitioned to try out for a girl's team just so they can "hurt" girls. I cannot see it happening.
If it helps people understand those born transsexual or even transgender better then it is good and besides the only ones that will transition at that age are those born transsexual and as someone that was out about that part of my life from 13 1/2 to 25 when I had surgery I can tell you fitting in is more important than sticking out. Since there are few if any surgeons that will perform SRS until children reach 18, although 17 is a possibility, I see most of this as harmless because those born transsexual rarely do anything stupid.
Sometimes you have to look at the bigger picture and helping transsexual and transgender kids of any age is that part of the bigger picture for me.