‘Yes. I suppose.’ I see the flicker of a smile on the edge of her lips before it passes. ‘You are looking at me weirdly. Will you just tell me why, because you’re beginning to freak me out.’

‘I’m sorry.’ I hold up my hands. ‘It’s just so much has happened. I’m relieved to be back. And safe.’

Bonnie seems to accept this but says, ‘So I’m assuming you did go back and see Iona’s mother on Sunday? When you told me you were coming home.’

‘I did.’

‘Right.’ Her shoulders rise and fall quickly as she battles her need to know and her resistance to hearing it.

‘Iona is definitely not your sister,’ I tell her.

She looks up.

‘I promise. She isn’t.’

‘How do you know?’ she asks, her breath slowly releasing.

I open my mouth to tell her it’s Jill, but for now something stops me. Instead I reel out another lie. ‘She showed me a photo of the baby. It looks nothing like you. She had ginger hair.’

Bonnie looks away as tears swim to the corners of her eyes. ‘Oh God,’ she says finally. ‘Oh my God.’ She lets out another deep breath and laughs as I slide on to a stool opposite her. ‘I was so sure Mum was lying. But she’s really not?’ She turns back, her eyes imploring me. ‘You’re telling me the truth.’

‘I am, Bon,’ I say, reaching for her hand. ‘But—’ I start as she carries on speaking over me. I can’t let her revel in relief when I still need to tell her what she’s most dreaded hearing.

She is talking about Mum, bringing up the Stay and Play sessions again. ‘Maybe it was my jealousy of Danny,’ she says, reassuring herself there was nothing more to it. ‘Maybe that’s why they took me. I mean, I hated him as soon as he was born.’

‘That’s really why you didn’t get on with him?’

‘Yes. I think it was really,’ she says.

‘So what about me?’

‘Oh, you were different. I couldn’t shake you off. I tried, but you just hung around me, and in the end I suppose I grew to love you.’ Her voice has the carefree tone of someone who’s received good news.

‘You know, I read this article about being the oldest sibling the other day,’ she starts, and when she turns back to me the edges of her mouth twitch up.

‘Oh yeah?’ I smile.

‘It said one of the most positive experiences of being the oldest sibling is nurturing the younger ones. Apparently my doing that has expanded my ability to be sensitive to other people’s needs. Think I got that spot on, didn’t I?’ she asks, her eyes sparkling.