Can my father do this legally?

Both my parents have made their wills, they are elderly 80 and 88, they are separated but still married, one lives with me, my dad in California. My mom/dad own a piece of property in Mx since like 30 yrs. ago. My mom when she made her will, she left her half to me and my dad his other half to me in his willl, even though they werent married in mexico just in the USA, is this legal? Both wills were notarized.