1. Your mistake TS is to let your wife know how much you are earning. When my wife asks me how much I make, I just tell her a 3k figure with a payslip as proof.
2. Shared responsibility is important. It helps to foster a teamwork mindset. Marriage is about growing together and it takes two hands to clap.
3. Now and then of course must pamper wife. Bring her to a nice date, buy her gifts, sponsor a family holiday.
4. Have a monthly finance meeting with your wife and have a clear set of financial goals - retirement money, assets, liabilities, contingencies, risk, insurance, etc.
5. Reinforce your responsibility and communicate your expectations and negotiate from there occasionally. This is important!

In your situation, to educate your wife get an asset under her name (can be a car/house) and help to pay the deposit/downpayment. Then ask her to pay for the installment. She gets the sense of ownership, responsibility and financial education.

Just my 2 cents.