WHOA here is my .02
If you are independnet, not for profit, SEPARATE from the school distirct, 100%, then most likely you can pray all night long if you want, in theory (doesnt mean some parents wont protest).
IF however, you are DEPENDENT, an arm of the school/district, if I were you , I would give invite Dr Lawyer of district counsel to my next PTO meeting and pick her brain on this one.
But no matter what you do, prayer wise, you are bound to offend someone in your parent body, so why risk alienating even one person with such a provocative stance, bringing prayer to a PTO meeting??????
As you know there are people trying to omit the word god from the morning pledge, surely you will have people all over your back quick like, if you bring in a full prayer to a PTO meeting, regardless of your tax filing status, indep or dependent ie, driven to be free or driven by separation of church and state, respectively.
And at the end of the day, dont yur bylaws stipulate something about being Apolitical? ANd not pushing your own agenda etc? I should think religion is tantamount to politics, in this day and age. IMHO.