Real estate search by spouse

A few months ago my uncle had a stroke and he’s now bed ridden and 100% dependent upon caregivers. He can’t speak or write and seems mostly out of it. My aunt, who is married to my uncle, was in the dark about a lot of things including a lot of their investments. She suspects he has real estate somewhere but he hid tax documents. Nice guy…. Since she is now paying for his nursing home care, she needs to locate all of their marital assets.

Would a realtor be able to search a tri-state area for real estate in his name? Obviously she’d go with a local realtor, but I just thought of this and wondered if the MLS would have this info.

Thanks for any insight.