I believe that the Bible teaches us to obey authority and schools have 
their own rules which are not against the teaching of the Bible. First, it is 
usual according to many of African cultures to keep our hair short 
clean. Girls among the Maasai, Kuria, Luhya, Abagusii, Agikuyu and even 
the Miji Kenda, keep short hair. So we are first Africans then religion 
comes in. So it is wise for these parents to understand that African 
beauty included short hair for girls- look at Lupita Nyongo and even the
 Late Miriam Makeba.


       Secondly, anybody who has been in the 
Kenya school system understands that it is not easy to take care of hair
 while in school. Students need at least 30-45 minutes to clean and comb
 their hair. So a girl would take approximately 1:30 minutes to prepare 
every morning. While she would be doing all these girls with short hair 
take only 15 minutes to prepare and start the morning prep. I have 
taught in girls schools and I have seen this many a time.  
        
Thirdly, what the Apostle Paul is speaking about here, is about the 
believers' faith and practice in worship and the passage specifically 
concerns married women and their husbands. Our girls in schools are not 
married. The Greek word used in I Cor 11:13-23 is 
gunaikos which means 
woman as in a married woman. The word 
Korë is what would refer to a girl
 or maiden. Therefore we can conclude that long hair is a sign of 
beauty for the married women's husbands not for everybody. That is why they were required to cover their heads.So when we look at the Pictures below which would be considered to be siutable signs of humilty in worship?


      
        Fourthly if a woman has no hair on her head then it was a 'shame' but 
not a sin and this was according to the prevailing culture of the Corinthians. So shaving of hair is not sin. Among the African communities,
 shaving hair signified morning or undergoing some rite of passage. 
Those cultures that practice circumcision, require the young boys to 
shave their hair before graduating and on the day they come out of 
seclusion  they are deemed smart if they have clean heads. So the parents should interpret our culture in the light of scripture. It is not sin for girls to shave their hair neither is it compromising the gospel.