Yes,the Catholic Church used to not condone sin.   It is mostly Caholic prolifers that have condoned sin and brought media attention stating that the pregnant girl should graduate with her class. Yet these same prolifers wiil take zero action when 12 Pseudo Catholic universities will allow pro abortion speakers at graduations. Thousands march in DC but only 88 prayed the Rosary outside Notre Dame when pro abortion anti Catholic president invited to speak at graduation.  They even removed crucifixes at the command the former president.  Most of "Catholic" prolifers vote for pro abortion candidates. Yes, the school is heretical sect. However, it is more " Catholic then most novus or do ..

Is the girl married?  I would guess, no.  Most are not to get state benefits.  They should be directed to finish school with a diploma, if not a GED.

The school is not Christian, but part of a heretical sect. The Catholic Church would have done something like this prior to the council.

The Sisters of the Holy Family are the same way about this. 

Society used to have proper sympathy for widows and orphans, now it's for unmarried women who conceive- and sometimes purposely for whatever reasons. (At least the divorcee with children tried to do it right in the first place. Generally speaking most women don't plan their weddings with the expectation to be soon divorced and left struggling with children.) "Single mothers" used to be called "unwed mothers" . While people often felt sympathy for a girl who was used and discarded , now they're  celebrated. (For example, they didn't get baby showers - people dropped off necessities quietly.) Pregnant teenagers certainly didn't walk the stage at graduation, if they were lucky there was a program for home study that allowed them to get their diplomas without attending. (and they most certainly need to finish their educations for the sake of the child) It irks me when they announce they are hard-working "single-moms" like they think that they should be getting some kind of kudos and perks from the rest of us.

Years ago, some neighbor kids were pestering my child every day, calling him "b-----d". I finally went to the grandma they lived with and complained. To my surprise, she called the children in and explained the specific meaning of the word to them, and informed them that since they themselves were the ones who fitted that description rather than my child, they should probably stop doing it. It stopped.

If the girl was visibly pregnant the banning would be from giving scandal.  If the girl were not visibly pregnant I am mystified by the ban.  An unrepentant sinner would be banned as a form of shunning, according to the dictates of St Paul.  More details are needed to give meaningful commentary...