While you won't like this £2000 is a fairly small portion of what you're committing to in commercial training on the basis of a gamble that she might get a job at the end, so at least you have lost relatively little so that when you do have to fork out more, you'll be paying by credit card. You could have lost £60k!
I'm sure she's a smart girl and will do well but this is one of those things that happens, not just in flying but in all sorts of ways, my wife lost her wedding dress a few weeks before we got married because a place went bust and while
Everything in the end turned out okay, it's not like the dress was doing the actual getting married....
People do say "don't pay for anything up front" it doesn't always wash in many lines of work, sometimes you're left with no choice and you have to pay up front, when you do use a credit card even if it costs you slightly more.
Flying schools go bust frequently and they don't go a little bust so normally the bank is the one that appoints the administrator and the administrator (normally a subsidiary of the bank) is the one that gets paid first, after that there's rarely any money left but you should definitely apply to the administrator for recognition as a creditor, you may get something.
As for Maria, she is the owner, the buck stops right at her feet and while Ted ran the business Maria is the one that has the legal responsibility to ensure that it is run properly. If you can prove that she didn't then the limited liability becomes significantly less limited.