In short, if her own husband cannot inspire her, no YouTube video is going to get the job done. Sorry, you're going to need to put in effort and be patient.
Funny, my DH has done almost the same thing - was sick and went to a Minute Clinic that wasn't covered and also called his family "just this once" in Canada without our prepaid card.
When stuff like this happens, I don't yell or put him down - he didn't do it to be malicious, it was more of an "in the moment" decision. When he gave me the Clinic bill, and I saw $90, internally I wanted to say WTF? But, I said something like, "$90 bucks, shoot. Well, we can just substitute out a couple of meals with lentil soup" - and make sure that I did it! The 5th time that month we were having lentil soup he was like, "again?", "hey, had to make up for it somewhere". It got my point across without arguing or making him feel like a 'screw-up'.
When he called Canada and I got the bill, I was like, "ah man, you forgot to use the card - you really need to watch that". I just make sure I remind him to use it (he calls once a week), and I be sure to thank him and let him know how it makes it much easier to keep us on track.
The other thing we do when we go out to eat is we order something that we can "eat half and take half" - we do it under the guise of it being healthier (eat less). Then I take the leftovers and mix it with pasta, rice, eggs, or whatever to make it into a completely new meal - I'm quite the master at it and DH now even brags about my skills in this area as we're packing up our food.
My point is, she's not going to change overnight. I hate to break it to you, but I've been "working on my DH" for around 2 years now. He'll probably never be totally onboard, but that is not going to stop me from reaching my goal. I am making great progress as I now hear him talk about the kid at work who just bought a BMW and called him an idiot for financing it when he still has student debt; so my dinner conversations about our future are sticking, even if he's not perfect about it. I also tend to tell stories about other people (both good and bad examples) and let that sink in - never saying you should do this or that. Look for improvements, but don't look for perfection - you probably won't get it.
My other advice is.... lead my example. DH has changed a lot of his patterns because I have changed mine. It is contagious.
I refuse to nag (it's not the kind of marriage I want); I praise often. And I'm patient.