Yes, she came to the UK after the country joined the EU. I don't understand the relevance. She's lived here with her husband and family and just quietly got on with her life.
Unfortunately, she's now been forced to spend thousands of pounds to maintain the right to stay here, just because some people want burgundy passports, straight bananas (or is bendy ones?) and have some kind of quaint notion that the clock can be turned back a few decades to a time when the sun never set on the Empire. There are some, of course, who are just inward-thinking and parochial and don't like foreigners, but I'm sure you're not one of those!