I can answer your questions from the persepective of someone who attended private school (though not as a parent of a child enrolled in one):
1.What grade is/are your child(ren) in?
I attended the same private school from grades 5-12.
2.How long have & will he/she/they be in a private school?
See above.
3.What kind of school is it? (charter, religious, Montessori program, just private etc) What made you choose this kind of school over everything else?
It was a non-parochial private school.
4.What made you choose to send your child(ren) to private school in general?
We moved at the end of 4th grade, and while we were still in the same school district, my new elementary school did not have a gifted and talented program. I had been in an experimental accelerated and G&T program at my previous school, but since the new school did not offer such a program, I was told that I would have to just do the same work as the other students in the class, even though it meant repeating work I had already completed a year or two before that. My mother appealed to the school board to see if something could be done (to allow me to go next door to the middle school for certain classes or to be permitted to attend my old elementary school), but when they said no, she pulled me out and enrolled me in private school.
5.Is there a difference in class size, teacher accreditation, after school activities etc in your child(ren)’s school compared to the local public school?
The student to teacher ratio at my private school was 7:1, which was far lower than the student to teacher ratio in my public school. There might not have been as many activities, just because of the school's smaller size, but there were still plenty to choose from and something for everyone--sports, academic clubs, Model UN, committees, theater, music, art, and more. I was very involved in sports and activities during my middle and upper school years.
6.Is there something specific you hope your child(ren) receives/gains in the future because he/she/they attended a private school?
I received a top-notch education by attending private school, and the environment was much more conducive to learning than you find in most public schools. Yes, there were groups of people who were friends, and while you might call them "cliques," there was not the petty rivalry and snobbiness from kids in one group toward kids in another. We didn't have any fighting, bullying, teen pregnancies, or any of the other multitude of negative issues that a lot of today's high schoolers seem to be faced with.
Because of my grades, my SAT scores, and the reputation of my school, I gained early admission to my first choice school (an Ivy League University). 100% of my graduating class went on to four year colleges and universities, and with very rare exception, that is the case for every class that came before and after me.