Can you own a firearm if you're bipolar in Montana?

My wife has bipolar 2 disorder and gets the utmost care. She has her condition under control and checks in with her doctor twice a year. I like to go shooting and she would like to join me. I was considering buying her her own firearm and make it legally hers if possible. Can she legally own a firearm in Montana having bipolar 2 disorder? She will not apply for a carry permit, just ownership of the gun. Thanks for your input.