My wife used to work for my company and contributed into our Solo 401k. Can she borrow some of her funds as a loan even though she doesn't work for the company anymore?
Yes, the funds may be used for a participant loan. If your spouse is no longer working for the company, she can no longer make contributions to the plan. The loan repayment can be made from a variety of sources (i.e. income, personal savings, another loan, etc).