Most 14 year old girls don't need any influence from their mom to not want to leave their friends for a weekend. While it may become more inconvenient for you, you might be able to make some headway if you allow her to bring a friend along on some of your outings or even to stay over night.

The good part of this is that you'll get a chance to spend time with her friends and see what kind of people she's hanging out with and what kind of dynamic they form together.

The bad part is that you're the male parent and her friends are undoubtedly girls. The friends' parents will have to find you trustworthy and you'll have to understand the proper way to act around teenage girls. Both of those things are good for any parent.

If this is an option you're willing to consider, don't make it open ended, as in giving your daughter the impression it's something that will happen every visit. If you're willing and if her friends' parents are willing, you can also probably expect some begging and sulking those times when you don't invite her friends along. Speaking as a former 14 year old girl, I can say the pull of being with friends can be unbearably and unreasonably strong at that age.

For your own sanity, you probably don't want to create a situation where you're parenting both her and her friends. But if it's at all possible, I am a strong advocate for non-custodial parents getting to know their child's friends and the friends' parents.