First Solar: Why Sam's Daughter-in-Law Is Wealthiest Walton by Gwen Moritz Posted 7/26/2010 12:00 am Updated 4 years ago An early investment in First Solar mean John Walton's widow is wealthier than his Wal-Mart heir siblings. Want the Full Article? Get Unlimited Archive Access for $19.95 per Year Readers must pay to access stories older than 20 days. Purchase Now Already have archive access? Login to view this article.