A donation site for those needing help.
As far as I know there is no such facility yet.
I do know there are several charitable people preemptively stockpiling coins against a time when speculators and/or recreational users push CANN toward parity pricing. With CannabisCoin still in the penny range at the moment though CANNdy is still quite affordable where available.
You are correct in thinking that charitable funds/portals should be established/controlled by the dev team as there have been several scam attempts already, particularly through the IRC channel as (an) imposter(s) seek "donations" or "loans" from regular users.
On the topic of how charitable funds could/should be distributed it might be best to arrange that through dispensaries as they are most likely to know and deal with hardship cases. That will help keep funds directed to those with a genuine need and help screen out the scammers seeking to exploit good people's charitable intent. Sadly there are ample examples of people pretending to be or to represent those that are genuinely in need simply to harvest donations out of pure greed and I suspect the kind of portal you describe would be a magnet for those with ill-intent.
Rest assured this has been and will continue to be discussed at length as the most useful and least exploitable solution is sought.
Your focus on medical marijuana patients is appreciated.