"Wife needs me to be a guarantor for the property she found."
I’m guessing that would make you financially responsible if she defaults? If this is the case, can you comfortably afford to cover this? That is the first consideration.
If no, then there’s your answer.
If yes, then talk with her about it. Express your concerns and expectations. You could even draw up a contract.
M: A really long time. Crisis: 5 years. She's still worth it.
Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl