While you were away on summer vacation, one of Dallas’ high-flying real estate couples was having a much harder time. Nicky Sheets was sentenced to 40 months in federal prison for tax evasion, and he was ordered to repay $2.4 million in back income taxes and penalties. His wife Eleanor Mowery Sheets pleaded guilty in July and faces up to four years in federal prison and at least $400,000 in fines. Her sentencing will be next month on October 12. Their $1.3 million Preston Hollow home was seized by the IRS this summer.