Catherine Orr is 19 and is a non-identical twin.She tells us about her relationship with her sister,Michelle.

How do you think it is different being a twin?
'I think it's very different.We've been through exactly the same things:the same birthdays,the same parties,the same first day at school,the same evil maths teacher.'

Do you think you and Michelle are more similar than ordinary sisters?
'Definitely.If I don't like a film,then neither does she.We pick up the phone at the same time to call each other.If I get ill,so does she.'

Do you get on well with Michelle now?
'Yes,I see her about once a week,although it doesn't make much difference if wee see each other or not.We always know how the other is feeling.I think it's hard not to be close when you have known someone your whole life.'

What were the best things about being a twin as a child?And now?
'You have someone who knows you almost as well as you know yourself,someone who is experiencing all the same things as you.Now it's great because we have almost exactly the same memories.She is my memory sometimes.'

What were the worst things?
'People called us 'the twins' as if we were one person-I hated that,and so did Michelle.Some people also used to save money and buy one birthday present for both of us!Also Michelle was good at sport and I was terrible-that was difficult for me.'