For someone like her to be breathless - is certainly a sign that something serious can happen to those that catch covid. This, while not happening to everyone is getting more attention now: Coronavirus: Thousands say debilitating symptoms last 'for weeks' - BBC News https://www.bbc.com/news/health-53269391
The common theme on the Slack group she is on, is that these are younger and healthy people, and that their covid was not particularly severe.
She also struggles to concentrate for any length of time, even reading a kids book to the children can be too much for her. There is no way she could work right now, and can't even do much more than supervise the kids for short periods of time - I am very lucky to have a flexible employer.
This appears similar to post viral syndrome or ME - and is happening at far higher levels than seen with our more common viruses like the Cold or Flu - though was also seen in people who caught SARs - it was not questioned that a percentage of those who had SARs were ill n months later, I'm sure in time it won't be for covid too. Just in tne mean time it means people believe the only risk is of death and that it will only affect the old and infirm.
Does COVID-19 cause breathlessness in a tiny percentage of people who caught it? Possibly, it's a respiratory virus after all. Does it cause loss of concentration? Hmm, maybe, who knows. The body works in mysterious ways. But if it can cause that then more or less any symptom at all is fair game.
Seen another way, do people with wifi sensitivity truly feel headaches when wifi is turned on? They certainly believe they do, their suffering seems to be real, yet we know their self-diagnosis cannot possibly be correct ... at least not without significantly rewriting the laws of physics and biology as we know them.
It may be that your wife should lose the Slack group and see a doctor. The risk is that the collection of symptoms she's reporting (which have no known link with respiratory diseases) actually have another cause and COVID is a distraction. It could be an undiagnosed case of something else that needs attention. We know that COVID is being spuriously linked in the media to all kinds of random conditions and symptoms, and especially when in a community of other sufferers, it's possible for incorrect inferences to be made.
https://news.google.com/search?q=australia%20tower%20block&h...
It's completely insane, unbelievably nasty, truly evil. The virus is not dangerous. I'll repeat: the virus is not dangerous. Excess deaths in the UK, relatively badly hit by a series of bad decisions, matches the famous plague of 1999/2000. You probably don't remember that one, because nothing happened.
NZ meanwhile is now terrified of re-opening their borders in the belief that this NOT DANGEROUS virus can be kept out forever. They have no plan for how to do this without going full-on North Korea. It's also incredibly self destructive. The Virus Is Not Dangerous.