Below is the full letter written by older sister Renu which has been seen by the BBC:
Dear Mr Javid,
I write to you on behalf of both myself and the rest of Shamima Begum’s family.
We are, as has previously been expressed through our solicitor, disappointed with your decision to begin the process of stripping Shamima of her British citizenship.
Firstly, we wish to make clear, that along with the rest of the country, we are shocked and appalled at the vile comments she has made to the media in recent days.
These are not representative of British values, and my family entirely reject the comments she has made.
My family went to every fathomable effort in February 2015 to attempt to block Shamima from getting into ISIS territory.
We contacted and cooperated with all the relevant government agencies in both the UK and Turkey to try and stop her progress.
Unfortunately, our efforts were in vain.
That year we lost Shamima to a murderous and misogynistic cult.
My sister has been in their thrall now for four years, and it is clear to me that her exploitation at their hands has fundamentally damaged her.
I have watched Shamima on our televisions open her mouth and set fire to our nation’s emotions.
As we have already expressed, we are sickened by the comments she has made, but, as a family man yourself, we hope you will understand that we, as her family cannot simply abandon her.
We have a duty to her, and a duty to hope that as she was groomed into what she has become, she can equally be helped back into the sister I knew, and daughter my parents bore.
We hope you understand our position in this respect and why we must, therefore, assist Shamima in challenging your decision to take away the one thing that is her only hope at rehabilitation, her British citizenship.
Shamima’s status will now be a matter for our British courts to decide in due course.
We seek solace in the fact that the institution of our courts as independent arbitrators of this nation’s laws have served as a bastion of good practice to the world.
My family trusts that this institution will properly perform its functions and entrusts Shamima’s future to its decision-making process.
Neither myself nor any of my family have had any contact with Shamima.
We have discovered from media reports, along with the rest of the country, that she gave birth to a baby boy.
We were pleased to learn from your comments in the Commons that you recognise my nephew, Shamima’s son, as a British citizen.
As a family, we ask now how we can assist you in bringing my nephew home to us.
In all of this debacle, he is the one true innocent and should not lose the privilege of being raised in the safety of this country.
We request that your office contacts our solicitor, Mr Akunjee, to discuss the practical mechanics of how to help my nephew find his way home.