14-year-old actress set for nude role - Does this goes too far?

No. Having a nude role, does not necessarily indicate there will be anything explicit showing on film, it just implies a depiction of the actor/actress as being "conventionally" nude. This could simply be for example Julia Roberts taking her towel after a shower and holding it open for someone in the background, so as it is "implied" she is nude, but we see no explicit nudity. The same is probably the case with this script. And the script, btw, simply states that they undress each other. The director can shoot that any way that seems fit. Dont believe every sensational thing you read.