By searching the internet I found that a possible solution for your aunt is to apply for "
Discretionary Leave"
A good discretionary leave application will seek to argue a person’s circumstances and backgrounds such as their age, length of residence in the UK, strength of connections within the UK, personal history including character, conduct and employment record, domestic circumstances, previous criminal record and nature of any offence for which a person has been convicted, compassionate circumstances and any representations received on the person’s behalf. The Home Office will consider whether the person has ties back in their native country of origin or the country where they would have to go to if returned, and also if this would affect any children of the family.
Where an overstayer/illegal entrant has established a family life in the UK and they have a partner or children, then it will also be possible to argue that discretionary leave to remain is granted as it is in the ‘best interests of the child’. A general legal principal is that where a child has been in the UK for more than 7 years, then the Home Office could consider that removing that child (along with their family members) would be against the best interests of the child. This is because the child will have integrated into British society; would be involved in full-time study with a routine and his/her peers/relatives in the UK and it would therefore be deeply unfair to penalise the child by removing him/her with their the parents due to the parent’s decisions which resulted in the child having no lawful status in the UK.
