Citizenship for my wife

Hello everyone, my wife is from brazil and living in Germany for 6 years while we are married for 5. We tried to get her the german citizenship already but she got declined, because she is not coming up for her living costs yet.

For reference: I am a german citizen and unable to work for more than 3 hours a day and my wife is not finding a Job. She has some troubles to get her next german course approved by Jobcenter since she had to cancel it two times for medical reasons. She though passed all the previous ones easily.

We are actually a little confused since one problem keeps the other alive. What are possible ways out of the loop? Thanks in advance :)