I worked a short term job awhile ago that was very well paid. It was in a different city, so I was living in a really small shared apartment. And I was mainly personally concerned about work. So I was willing to spend money to save myself time.
I've never really had a problem with saving money or being frugal, but I discovered I really liked having a lot of disposable income. I didn't really have a lot time or space to cook, so I got a lot of easy to prepare foods and ate out a lot. I really liked eating out at a restaurant with coworkers for lunch. I liked eating out several times a week. I preferred taking toll roads instead of dealing with traffic jams. I liked going out with other people and not worrying about how much I'm going to spend.
My car also ended up breaking down and I ended up spending a lot of money on repairs. It was an old and inexpensive car, but it was in good condition. But the bill was high enough that I would have probably sold it as is or parted it out if the rest of the car hadn't been in such good condition. The money wasn't my only problem in that situation. I was also concerned about the stress and time I spent dealing with getting it repaired. I'd say those two were about equal. In fact, if I had been trying to turn that short term position into a full time position it would have been better for me to financially to just take the easiest method of repair, not worry about it, and spend my time and energy trying to get hired on full-time.
The idea that it was a better decision for me to use my money to save me time and energy was a completely new experience. When I didn't have a well-paying position I wouldn't spend money needlessly without feeling guilty. And I'd take care of normal adult responsibilities, like taxes, myself. But back then I wouldn't have thought much about paying other people to take care of it for me.
I was having a decent amount of cognitive dissonance between what I was used to and what I as experiencing. I was raised middle class, but I've definitely not had money. I remember once one of my friends was just out of college and looking for good work. And they were happy about a part time position that paid under twice minimum wage. It definitely seemed like a decent job working with great coworkers for fair pay. But I also remember working with someone who was full-time at that position and was making more money than me. We had a conversation where he mentioned that he didn't cook at home that much, he usually just ate out at local restaurants for lunch and dinner. He thought that there was a lot of good inexpensive food close by, and didn't really care about saving money by cooking because his pay per hour came out more than what he would save. And while you could probably point out how much money he spent in a year just on eating out, it was still a completely rational decision. I don't think it would have ever prevented him from saving for retirement, getting a decent place to live, or basically anything that you need to do when you get a career.
So I don't think it's stupid not to take his money if she is really insecure about the income gap. Going from 12k a year to 9k a month is going to be a huge change for her. And I definitely would not want to make it in the opposite direction. I kno