hmm.... Why would she ask you that question? That's weird.... but probably you could because if she knows your private key she should be able to access to your account.
Bible made it know that husband and wife are one, so what ever you have belongs to your wife, using myself as a case study, base on the question I have to realized that our wife have to know the basics knowledge of cryptocurrency in case of death occurrence in human life, and if death occur she can take care of the family with your Bitcoin investment, to make the life suitable for our kids, so that should one of the reason while we should not hide our coins for our wife.