convent schools and lesbians

Recently I had a conversation with a colleague in the pantry. One of those water cooler conversations.
This conversation was about her little girl starting school soon and how it was getting very competitive amongst parents trying to get their kids into good schools.
In the area where she lives there is a pretty good convent school and I asked why she wasnt considering that school

She didnt want her daughter to go to an all girls convent school as she thought thats where Girls become lesbians.
How interesting.  Do we tend to be attracted to the same sex if we go to a single sex school?
 Is there a higher percentage of women becoming lesbians if they attended a single sex school?  I wonder if anyone has done a study on this?
I went to a convent school and yes there were alot of girls having crushes on each other and even starting to explore with each other.  I do know that going to an all girls school made me shy and totally unable to interact with boys and later on men as well but I didnt have the girl crushes. I was too busy looking at the boys from the nearby all boys school.  Would boys then tend to be gay if they went to an all boys school, or is this only applicable to girls? 

But its an interesting thought,  about the connection between convent schools and lesbians.