For most, Mothering Sunday is a simple annual event to celebrate Mum.

It’s a day that has special resonance for adoptive Mums and their children.

Around three-quarters of children who are adopted today will previously have suffered abuse or neglect with their birth family so parenting them can be tough but also hugely rewarding and inspiring.

The bond between adoptive parents and their children is often extraordinary, with love and admiration on both sides.

But Mother’s Day is a celebration which can prove complicated as adopted children have complex feelings about their birth parents.

Adoption UK wants to celebrate adoptive Mums across the UK by shining a light on their commitment, love and resilience - and who better to provide this testimony than adoptees themselves?

In a letter to her adoptive mother Jane, university worker Polly, who lives in London but grew up in Yorkshire and Lancashire, writes: As an adopted daughter I came to you with a warning label – I was not thriving. I was expected to have educational and emotional difficulties. Before you were even able to hold your baby in your arms, you had been told that your baby was broken.

This didn’t matter to you. From that first moment that you looked into my eyes we finally had what we both needed: a family. You devoted every second of your life from that day to fixing what you had been told by professionals might be unfixable. Against every expectation I didn’t just begin to thrive, I began to achieve.

Polly’s letter continues: I could not be even a fraction of the person I am today without your love, dedication and incredible belief in me. All the best parts of me, of my character and my personality, are down to you and and the great example you have always set for me.

Her letter concludes: Thirty-seven years on, that baby who was not thriving has a Master’s degree, a job in a university, a wonderful husband; she has travelled to five continents, sung in the Royal Albert Hall and even dabbled in stand-up comedy.

19-year-old Megan Alston, from London, writes to her mother Regina: You’re my Mum you lie with me until I fall back to sleep after I’ve had a nightmare. There are no secrets between us. No problem I’m afraid to share.

You might have missed my first word and you didn’t get to see me take my first steps, but those aren’t the things that make you my mother. It’s the way you call me when I’m home late, make soup for me when I’m poorly. One day I hope I can adopt too and give my children the wonderful life you’ve given me.

Daniel Coole,from Cheshire, writes to his adoptive mother Jan: Mother’s Day is a stark reminder for some of us. But then, you remember that something incredible happened when you were at the most vulnerable stage of your life. In walked somebody who cares for you, who protects you and who nurtures you, and the best part of it all? It was all by choice.

A mum is the person we reach out for when we fall over. It’s the face we search for in the crowd during the school plays. It’s the taxi driver who just wants to make sure we get to our destination safely. It is the person who knows us better than we know ourselves. 

Daniel goes on to write: Thank you for giving up a part of your world to ensure that I could have the best shot at this thing called life. Thank you for showing me the way every time I get lost on this journey. Thank you for being my best friend. Thank you for being so brave and selfless to ensure that I was happy and safe. Thank you for allowing me to grow into my own person whilst cheering my triumphs from the side-lines.

The letter ends: I am sorry for the times I told you that you could never be my mum. It was never about you or your parenting skills. It was about me being confused and frustrated. You always have been, and you always will be, my mum.

In a letter to her mother Jane, the West End performer Shona White, who lives in London but grew up in Fife, Scotland, writes: …what you (and Dad of course) did for me all those years ago was the best thing that ever happened to me.

You have supported me in all my hopes and dreams and helped me achieve success in my chosen career and for that I will be eternally grateful.

Thank you for putting up with me through the more challenging times and for all the happy memories we have created together.

Olympic silver medallist and former World Champion Jamie Baulch, from South Wales, writes to his mother Marilyn: Words can’t describe how amazing you are. You have helped me throughout the whole of my life. You have given me opportunities that I wouldn’t have had if I weren’t with you. You have guided me throughout my whole life. My athletics career would never have happened if it wasn’t for your support, love, guidance and attention. I owe you everything and I love you with all my heart.

And BMX champion and Hollywood actor John Buultjens who grew up in Glasgow and Dundee but now lives in California, writes to his mother Marianna: To say you have been such an inspiration in my life, is an understatement, you are so much more. I am very thankful that you choose me to be your son, back in 1982.

Around three-quarters of children who are adopted in the UK today will have entered the care system because of the severe neglect and/or abuse they experienced with their birth parents.

Adoption gives these children, many of whom have complex needs, a second chance of experiencing enduring family relationships.

Adoptive parents provide stability, permanence, a new sense of identity and the love and nurture that all children need - as these letters eloquently demonstrate.

Adoption UK's purpose is to give voice to adoptive families and to ensure that the right support is there for them.

Anyone experiencing difficulties is urged to become a member of Adoption UK and contact our helpline: https://www.adoptionuk.org/one-one-support/helpline