Awan-Legal : Hi
Awan-Legal : It appears as though her man was a dual British citizen and German national.
Awan-Legal : UK law permits dual nationality but you would need to check with the German authorities or a German lawyer whether dual citizenship is allowed in Germany (as I am a UK solicitor and can only deal with English law).
Awan-Legal : Bear with me as I am just drafting an answer to your question so will come back to you shortly with n nswer.
Awan-Legal : If her child is European, then she can remain in the UK on this basis:
Awan-Legal : I am a non-EEA parent or primary carer of an EEA national self-sufficient child - can I apply to remain in the UK? Close Following the ruling by the European Court of Justice (ECJ) in the case of Chen (ECJ C-200/02) the parent(s) or primary carer of an EEA national child is entitled to reside in a Member State with a self-sufficient EEA national child solely to facilitate the child in exercising their Treaty rights. The child must have comprehensive sickness insurance and be self-sufficient. This means that they must not rely on funds earned by a non-EEA national parent(s) or primary carer in the UK, unless this comes from legal employment or self-employment (if the parent(s) or primary carer is in the UK on a work permit). In cases where the non-EEA national parents or primary carer wishes to reside in the UK on the basis of their relationship with an EEA national self-sufficient child, then they can apply for leave to remain under paragraph 257C of the Immigration Rules. The leave granted does not allow the parents or primary carer, the right to work in the UK and does not lead to permanent residence or indefinite leave to remain. Applications made on this basis are free of charge and should be submitted on an EEA2 form.
Awan-Legal : The form can be found here:
Awan-Legal : http://www.ukba.homeoffice.gov.uk/sitecontent/applicationforms/eea/eea21.pdf
Awan-Legal : Alternatively, if her child is a British citizen then she can apply for regularisation of her status (leave to remain in the UK) on the basis of the child's human rights by relying on the case below, although this may not be very strong until her son is in education:
Awan-Legal : (as the UKBA may state he is young enough to adapt to life abroad although it can be argued he has right to education in the uK as a British citizen)
Awan-Legal : In ZH (Tanzania) v Secretary of State for the Home Department  UKSC 4 (1 February 2011) the Supreme Court turned its mind to whether (and when) it would be permissible to remove a non-citizen parent of a British child from the UK; and also, more broadly, the weight to be given to the best interests of children who are affected by a decision to remove one or both of their parents from the UK.
Awan-Legal : I would suggest going to a solicitor to assist with the application as these types of cases can be complicated.
Awan-Legal : I cannot answer you questions on US law or commonwealth countries as I deal with UK law but by having residence in these countries would not lead to any rights to remain in the UK on this basis.
Awan-Legal : If she is removed from the UK, she can return at any time depending on the circumstances but may be banned for between 1 to 10 years unless she is coming back to the UK to join family. Her best route would be to make one of the applications whilst she is still in the UK.
Awan-Legal : Please click accept on my answer.