Since I joined this forum I have grown more mature and understanding of relationships. Firstly I am going to answer the title of this thread, regarding dating.
To begin with, I think we should also understand things like puberty, hormones as well as peer pressure from media and society, and over-sexualisation from media. Also understand that in the western perspective, the dating terms girlfriend and boyfriend actually describe being partners, similar to what a husband and wife is.
I have pondered, contemplated and understood some things:
One thing is that, historically and world-wide, people used to get married usually in their teenage years or perhaps early adulthood/ early 20s, and this was in tune with human nature (hormones, puberty etc). Look at the ages Guru jis got married. I do not even think the Guru jis or purataan sikhs/Singhs would consider it appropriate for anyone to marry at the ages people marry now, including the ages sikhs are now getting married at, especially in the west. We can exclude non grihast ashram following celibate/Behingam purash such as Baba Sri Chand, Nihang Singhs committed to doing sewa, sants committed to sewa etc.
Previous generations, such as sikh migrants to the uk, probably married at suitable ages. Parents from both western countries and India have not been able to well adapt these marital traditions to the desire to get married later due to issues such as studying at University. Only a minority of students are already married when they start university. I also know of a gursikh family whose daughter got married during university.
Human nature desires a partner (again due to puberty, hormones etc), but the pressure is again increased due to peer pressure, society, media, and of course age as well. Traditional arranged marriage provided a partner at an appropriate age. Modern arranged marriage is no longer age-friendly. The desire for a partner leads to getting a boyfriend/girlfriend, which of course is a partner as well isn't it? This is definitely not the gurmatt way or grihasti way, but sometimes this can lead to a grihast marital lifestyle. But in alot of cases it is a replacement. I can even say, for many people dating is now a marital type lifestyle as well, living in a family and having children, just like a married couple. But if you are sikh, then this isn't Anand Karaj though is it? It's more of a cultural thing in the west.
In punjabi culture, (I have also seen this in older punjabi movies) an unmarried man past his early 20s would become known as "Sharrah". That's like saying this person is past his marital age now. I actually saw in these older movies Mehar Mittal used to be the Sharrah flirting with single girls in a comedy way, sometimes getting married to one.
So to conclude, people are dating because children go past the age that tradition and gurmatt would recommend for marriage, and human nature and societal influences takes over.
OK, so many sikhs including amritdharis are not going for arranged marriages anymore. In that case, parents need to explain to the children concentrate on looking for a husband and wife, not to look for a boyfriend and girlfriend which is the western cultural norm.
Getting to know someone is very good for marriage, but there is no point in becoming constrained in a boyfriend-girlfriend partnership if your aim is to be in a marital grihast partnership such as through Anand Karaj.
FInally I will refer to the context of middle school. Are middle schoolers teenagers? I think at this age hormones and puberty start. Back in old times some people got married at these ages I guess. I reckon peer pressure is also leading to people dating at this age but then again, in the UK girls get pregnant at 12 in deprived areas yet people will say it is backwards to marry at similar ages. I would say marriage was mutually exclusive to bodily changes. As the law now dictates when someone may marry, then dating has replaced teenage partnerships in society.
I think your friend is either one of those "chalak" girls, or her hormones have taken over, such things happen to some young people earlier than others. I would be careful if I were you.
In the context of amrit-dharis dating. I know amrit-dhari families from indian backgrounds who would not dare date. I myself don't come from a gursikh family, but we wear turbans and are very traditional. Most amrit-dharis I have seen that date are ones that don't come from families that have a recent link to India or Punjab, like I had friends that were Amrit-Dharis but they weren't very traditional, their families came from other countries where the sikh sangat had become very modern and no longer frowned on dating, they aren't very desi and use condescending terms to describe punjabis such as "Indian Mentality". Just remember, Guru jis and purataan Singhs lived in desi society, and even the history in Gurbaani references this society as well.