From my personal experience I actually think that rugby as a sport is especially beneficial to young girls (possibly even more so than boys).
Teenage girls are under incredible pressure from social media and their peers to look a certain way to act a certain way- to be the "popular girl".
The core values of rugby are Teamwork, Respect, Enjoyment, Discipline and Sportsmanship.
Just taking some of these, girls rugby is massively social able, much more than the boys rugby- you only have to look at the joking around and laughs of the England team. Thats not to say they don't take it seriously but that they have so much fun in doing so.
Respect - girls are judged on whether they do their job on the pitch and look after their teammates. If a girl doesn't put the effort in then another girl has to which means she is more likely to get hurt.
Or more simply the girls really don't give a crap who you are dating, where you live, your skin colour, who your friends are etc etc . All they care about is that their teammates put the effort in which that stops or reduce the chances of the other girls being hurt.
It reduces the chances of girls being bullied at school - because the girls are incredibly loyal to their teammates (much more than the boys). And let's be honest you would have to be a special level of stupid to pick on one of the rugby girls at school.
Rugby as a sport is for girls of all shapes and sizes- your bigger girls for the forwards and skinny fast girls for the backs. They are all equally valued with a different job for different sized / skilled girls.
Teamwork- many sports favoured by girls tend to be individual sports (horse riding, swimming, tennis etc) because of the element of physical risk rugby creates a bonding amongst the girls far greater than other team sports.
So yes there is a physical risk to girls playing rugby but in my experience the benefits outweigh the risks.