Illescas and her British husband are planning to leave, after arriving two-and-a-half years ago from Germany. They came because her husband was "offered a brilliant job in London."
Illescas will join an exodus of tens of thousands of other EU nationals leaving Britain, a country many Europeans say is no longer welcoming.
"There's this really strong collective image of immigrants coming with their broken English to steal jobs and benefits, and scrounging the system, which is poppycock. But there it is, and it gets very tiring," she says.
Protestors carry a giant EU flag during an anti-Brexit march on the first day of the Conservative Party annual conference in Manchester on Oct. 1, 2017.
Largest dip in migration
Net migration to Britain during the past 12 months has fallen by the largest amount since record-taking began, with EU nationals making up the bulk of those choosing to leave, according to official statistics.
Many of the Europeans electing to do so are not the ones the British government wants to see leave; they are young, skilled and talented, filling the ranks of the National Health Service, the finance sector and creative industries. Others are crucial for the hospitality and construction industries. They are voting with their feet after being denied a say in the June 2016 Brexit referendum.
Because she will have lived in Britain for fewer than five years when Britain's scheduled March 2019 exit from the EU occurs, Illescas won't qualify for permanent residency.
"Being married to a U.K. citizen doesn't make any difference in that respect (in other countries, such as Spain, it does). There might be a grace period for the PR (public relations), but nobody knows for sure," she says. She and her husband have concluded it is better to go now before things become worse.
Reshaping labor market
The Resolution Foundation, a policy research organization, says the drop in net migration shows that Brexit is already reshaping the labor market.
"Businesses across Britain need to prepare now for a new era of lower migration," it says, warning a fall in EU migration will be felt most sharply in London, and in industries like food manufacturing and hospitality, which are heavily dependent on migrant labor.
Official government figures released last week show net migration to Britain fell by 106,000 to 230,000 in the 12 months to June, and the number of Europeans leaving rose by 29 percent to 123,000, the highest level of EU emigration from Britain since the 2008 financial crash.
Europeans are still arriving, and record numbers of the 3 million EU nationals already living in Britain are applying for citizenship or permanent residency, but uncertainty about the status of Europeans after Britain's 2019 exit from the EU remains.
FILE - British Prime Minister Theresa May is seen during a meeting at 10 Downing Street in London, Britain, Nov. 27, 2017.
An appeal from May
Prime Minister Theresa May has appealed directly to EU citizens living in Britain to stay in the country after Brexit, saying there's no intention of using them "as bargaining chips" in negotiations with Brussels over a trade deal.
"I couldn't be clearer; EU citizens living lawfully in the U.K. today will be able to stay," she said in one email broadside sent to tens of thousands of EU nationals.
May says her government and EU negotiators are in "touching distance" when it comes to agreeing on what happens to Europeans living in Britain and the 1.3 million Britons currently residing in Europe, including on their right to work and to own a business, their social security rights and reciprocal health care.
But there are fears among migrants that all will not be well for them after Brexit.
Government efforts to reassure Europeans have not been helped by frequent reports in the news and on social media about the casual and regular anti-migrant hostility Europeans say they have encountered in Britain since the Brexit vote.
A flood of stories about applications for permanent residency from Europeans being declined by immigration authorities is also prompting alarm.
On Sunday, the head of Scotland's Royal Botanic Garden, Simon Milne, a former Royal Marine, expressed his anger about his French wife of 24 years being refused permanent residency.
More than a quarter of EU nationals applying for permanent residency since the Brexit vote have seen their requests declined. Officials say applicants failed to supply sufficient evidence or their applications contained errors.
Veronique Martin, a French author, along with Italian interpreter Elena Remigi, published a book earlier this year, titled, In Limbo: Brexit Testimonies from EU citizens in the UK. The book contains more than 140 stories posted online by EU nationals worried about discrimination from the government and xenophobia encountered in everyday life.
"Many of our testimony givers have already left the U.K.," said Martin, "due to a mixture of discrimination from the government, deep anguish about the future and xenophobia."