A US citizen may file an I-130 visa petition for his wife and if she entered the US with a visa, she can apply for permanent residency with the I-485 application. There are several other forms that must be submitted, such as the I-864 affidavit of support and the G-325 biographic statement, but there are no fees for those forms. If you submit a complete package to USCIS, your wife could gain her lawful residency within 4 months depending on the USCIS office that interviews you.
If you confirm her eligibility with an experienced immigration attorney, she should apply right away. It sounds like she is eligible, and by not fixing her status, she risks being arrested and placed into deportation proceedings which are very costly and it can take many years to fight against deportation.