How can I explain to my daughter who is 13 why I ...

This is a delicate situation as the way it is presented could very possibly lead to future secrecy from your daughter about who her friends are. In my opinion, the best way to approach this situation is to begin asking your daughter some very basic questions about this friendship. What does she like about her friend? Why does she like spending time with her? Does she think she makes smart decisions? Etc, etc. Perhaps such questioning will lead your daughter to draw her own conclusion about her girlfriend's values. Maybe she'll have the opportunity to see her friend in the same light that you see her. Allowing her to draw her own conclusion with the values that you have instilled, will help to avoid resentment of the feelings you have formed about a friend she has chosen. If her friends' values are truly "distorted" and repel her own, some strategic questioning should help to clarify. However, keep in mind the possibility that regardless of our rearing, it is possible and sometimes inevitable that our children form their own unique values. I hope this helps.

hmm,13 is a hard age,not full grown and not a child either!i had the similar situation.what i told my son was,that i don't like his friend and i gave my reasons,this brought on many arguments from him,and knowing that he will continue to see this friend whether i forbid it or not,i told him to invite his friend to our house[that way i could keep my eye on both of them]he did go on seeing this friend for several months and one day,my son told me that he won't be inviting his friend over again,because my son finally saw what i had seen!sometimes,you have to let your children make up their own minds about their friends,cause if our children are raised with morals,they will see for themselves that certain people aren't right for them!if you forbid this relationship,then she will see this friend in secret and after that she will not tell you who her friends are and then start doing many things in secret!

the best thing to do is keep reminding your daughter of the things that you like to see in people and also ask her what she likes about this friend,

and what she doesn't like about this friend,also ask her if she agrees with the way her friend acts,in greece we have a saying"show me your friends,and i can tell what you are!"

oh,i just wanted to add when i was that age i had friends that weren't as moral as i was,but since i was raised with morals,i knew what was good or what was bad,yes they were my friends,but eventually i saw that they weren't the kind of friends that i needed,and i just had friends that had the same values as i did!

the best remedy for this is,to have her friends whom you approve of over more often,good friends are so much better at giving advice to your daughter than you can ever imagine!once this friend of hers is looked down by her other friends,she will get the picture,and cut herself off of this friendship!