A 33-year-old Nampa woman has been sentenced to up to seven years in prison for enticing a 13-year-old boy over the Internet. Canyon County prosecutors say Ruth Alvarez must serve at least 2.5 years in prison before she is eligible for parole. She also must register as a sex offender. Investigators say the boy's mother notified them when she found a letter Alvarez had written to her son expressing sexual interest in him and asking him to add her as a friend on MySpace. An undercover officer then posed as the teen during online chats with Alvarez, during which time the police say she made sexual comments. Alvarez pleaded guilty in September and was sentenced Monday.