We talk to girls about romantic relationships. Not always enough, and not always well, but we do at least recognise that they may need some preparation. We tell them that nobody should control what they wear, that jealousy isn’t proof of love and that they’re allowed to say no. We warn them about partners who demand passwords, isolate them from people they love or frighten them into staying.

But what if it’s a friend doing those things?

Friendship is one of the first places where girls experience love, loyalty, intimacy, power, jealousy, betrayal and heartbreak. Long before most girls have a romantic partner, they are already learning whether closeness requires them to surrender parts of themselves. And yet we often treat friendship difficulties as rather trivial.

“Just ignore her.”  “Find some other friends.”  “It’ll all be forgotten by next week.”

Sometimes it will be forgotten by next week, but that doesn’t mean it doesn’t matter now. Over many years of working with girls, I’ve heard them describe the tiny adjustments they make to remain acceptable. They know when not to admit they enjoyed something, what not to wear again and when to laugh even though they don’t understand the joke. They learn to pretend they don’t mind, not to disagree, not to appear needy and, above all, not to be weird.

From the outside, a girl may look socially successful. She’s invited to parties, included in the group chat and has people to sit with at lunchtime. Inside, however, she may be working terribly hard. There is a difference between being included and belonging. Inclusion means there’s a place for you at the table. Belonging means you don’t have to leave important parts of yourself outside before you sit down.

One girl I worked with told me that her friends liked her because she was easy going. This cost her. She minded when plans changed and nobody told her. She minded when jokes were made at her expense. She minded being expected to listen to everyone else while nobody asked how she was. Her place in the friendship depended upon her performing the easy-going version of herself. She had friends, but she didn’t feel known by them.

I also wonder whether we make friendship harder by asking young children, “Who’s your best friend?” It’s such an ordinary question. I’ve asked it too. But it suggests that friendship has a top position and that somebody choosing you above everyone else is proof that you belong.

Having a best friend can be wonderful. It can also come with an unspoken contract about who you sit with, what you share, whose posts you like and whether you are allowed to invite somebody else. Closeness can slip into ownership remarkably easily.

I knew a girl who had three very good friends. One made her laugh, one shared her love of drawing and the third understood what it was like when life at home felt difficult. Still, she believed something was wrong because she couldn’t name one of them as her best friend. She had friendship all around her and thought she had failed.

Perhaps girls need a more spacious picture of friendship. Different people can meet different parts of us. Not every friendship has to contain everything, and a friendship doesn’t have to last forever to have been real or valuable.

Then there’s the parental dilemma. Our child comes home in pieces because she has been excluded, ignored or humiliated, and every friendship wound we have ever had wakes up. Suddenly, we’re not only the adult in the room, we’re eleven years old again, standing at the edge of the playground, pretending we didn’t want to join in anyway.

No wonder we want to act. We draft the message. We diagnose the other child. We decide the friendship is toxic. We start arranging alternative friendships before our daughter has even finished telling us what happened.

Sometimes adults absolutely need to intervene. Bullying, coercion, threats, repeated targeting and frightened or unsafe children require adult attention. But hurt and danger are not always the same thing, and they don’t always need the same response.

A mother once told me that her daughter had been left out of a sleepover. She was furious and immediately began composing a message to the other mother. Her daughter stopped her and said, “I just wanted to tell you.”

Her mother had mistaken being trusted with the story for being appointed to fix it. That is so easily done. Perhaps before acting we could ask, “Would you like me to listen, help you think, or do something?” It returns some power to the child. It tells her that she isn’t alone and that we believe she may have some wisdom of her own.

I don’t think girls need another list of rules for choosing the right friends. Friendship is too human and complicated for that. But perhaps they do need permission to notice who they become around someone. Can they disagree without being punished? Can they have other friends? Can they say that something hurt? Is the friend pleased when something goes well for them? Do they feel bigger, smaller or more themselves after spending time together?

Girls also need to understand that a friendship ending does not mean they have failed. Some friendships change because people change. Some can be repaired. Some need more room. Some are precious for a particular part of our lives and then come to an end. Losing a friendship can be deeply painful without meaning that a girl has lost her capacity to belong.

On Monday 28 September, our Rites for Girls Women’s Hour will explore the question: what do girls need to know about friendship? This is an hour of conversation drawing on what we women have lived and learned.

What did you tolerate because you were frightened of being left out? Who allowed you to be fully yourself? How has constant connection changed friendship for girls? What do you wish somebody had told you?

We spend a great deal of time warning girls about the relationships they may have one day. Perhaps we need to pay more attention to the relationships shaping them now.