Marlies Haselton has called Britain home for more than 30 years.
The Dutch national married a Briton, had her children there, and considers herself "part and parcel" of the UK.
Until Britain's divorce from the European Union, she had never given a thought to her immigration status in the UK.
Haselton, 55, is among the millions of Europeans who have freely lived, worked and studied in the UK for decades, but whose rights are no longer automatically granted due to Brexit.
Britain's government introduced a "settlement" plan for the country's large European migrant community in 2019, and the deadline for applications is Wednesday.
From Thursday, any European migrant who has not applied will lose their legal right to work, rent housing and access some hospital treatments or welfare benefits in the UK.
They may even be subject to deportation.
Meanwhile, the freedom of movement more than a million Britons have long enjoyed in EU countries is also ending.
Those applying for post-Brexit residency permits in France also face a Wednesday deadline.
Campaigners in the UK are worried that tens, or even hundreds, of thousands of Europeans may not have applied in time.
Many older people who have lived in the UK for decades are not aware they have to apply, while official figures show only two per cent of applicants were 65 years old or older.
Many parents also do not realise they have to apply for their children, migrants rights' groups say.
Other vulnerable people, such as an estimated 2000 children in social care, also risk falling through the cracks and ending up with no legal status.
For Haselton and many others, it is a moment that drives home the impact of Britain's referendum to leave the EU five years ago.
"I don't feel settled," she said.
"I'm concerned about the future. I just don't have a safe feeling about growing old here as a foreigner.
"The sense of home I used to have is gone."
Britain's government says 5.6 million people - the majority from Poland and Romania - have applied, far more than initial estimates.
While about half were granted settled status, some two million migrants who have not lived in the UK long enough were told they have to put in the paperwork again when they have completed five years of residency in the country.
And about 400,000 people are still in limbo waiting for a decision, said Lara Parizotto, a campaigner for The3million, a group set up after the Brexit referendum to lobby for the rights of EU citizens in the UK.
"These are the people we're hearing from a lot," she said.
"You want to be secure and safe, you want to continue making plans for your future.
"You can imagine how complex it is not to have that certainty in your life right now when things are about to change so much."
In recent weeks, Parizotto, a 25-year-old Brazilian-Italian, has travelled with other volunteers across England to urge European communities working in rural farms and warehouses to sign up before it is too late.
Many Europeans, especially young people whose parents failed to apply, "won't necessarily realise they have lost their status right away," said Madeleine Sumption, director of Oxford University's Migration Observatory.
"For some, it will only become clear later on - for example, when they get a new job or need to be treated in hospital," she said.
"It may be many more years before the legal, political, economic and social consequences start to emerge."