Who is responsible for preventing girls from becoming sluts? It is distributed, with some actors having more than others.
But first, one needs to consider if entities that should have responsibility even see a need for slut prevention. How about society? Does it see a need to prevent sluts? In the old days, the answer was yes. Doing so was about many things that societies considered to be of value: societal monetary cost, improved mothers and children, more content people in the long run, etc. Apparently society does not value these much anymore; or perhaps it is rich enough to absorb the costs in terms of social services, welfare, etc. I wonder if society really made this design, or was it made for them?
Anyway that you look at it, for the others responsible for the prevention of sluthood, the situation is now more difficult without overarching societal support. This is probably why in the USA, home schooling has become more popular; allowing the parents to better control the environment that children grow in. Let us now consider the parents. If the Mom is a slut (or a unrepentant former slut, e.g. an alpha-widow), then all is lost. I have seen this situation many a time. The sins of the mother are visited upon the daughter. Assuming that the mother actually wants to prevent slutdom, how much responsibility is hers? There probably are many opinions out there, but I would say she has the majority of the responsibility. The simple reason is it is about being a role model, in both action and attitude. Good role models can make good things happen; bad role models almost always lead to bad results.
The father also has a responsibility. He should set the tone with respect to the expectations. The daughter should feel that by being a slut, she would be disappointing him greatly.
It is most definitely a greater challenge today to prevent sluttery in daughters. But with effort, it can be done