Appeal from the Circuit Court of the 13th Judicial Circuit, Grundy County, Illinois, No. 01--CM--1207 Honorable Robert C. Marsaglia, Judge, Presiding.
 The opinion of the court was delivered by: Justice Barry
 Following a bench trial, the defendant was found guilty of distributing harmful material to a minor (720 ILCS 5/11--21(a) (West 2000)). She was sentenced to serve one year's conditional discharge and four weekends in the Grundy County jail. On appeal, the defendant argues that the State failed to prove the elements of the offense beyond a reasonable doubt. We affirm.
 The events at issue took place during the evening of December 27, 2001, in Coal City. The defendant testified that she had a relationship with Richard Jurzak for about a year. After the relationship ended, the defendant told Richard that she would return photographs of the defendant and Richard that were sexual in nature.
 Jessica and Breanna Jurzak are Richard's daughters by another woman. On the evening in question, Breanna was 10 years old and Jessica was 12 years old. Jessica stated that she and Breanna were in the garage of her father's home when the defendant entered. The defendant placed an envelope addressed to Richard on a bench in the garage. She asked Jessica to give the envelope to Richard. The envelope was sealed with tape.
 The envelope is included in the record. In the upper left corner of the envelope, "J. Jurzak" is written in the return address position. Richard's name and address is written in the addressee's position. In the upper right corner is an uncancelled first class postage stamp.
 The defendant testified that she wrote "J. Jurzak" in the return address position of the envelope. She said that during their relationship Richard had referred to her as "Jeannie Jurzak," although they had not been married. The defendant also knew Jessica to be Richard's minor child. The defendant had placed a letter to Richard and the sexually explicit photographs in the envelope.
 The defendant alleged that she did not leave the envelope in Jessica's possession. The defendant said that she gave the envelope to Tammy Reynolds with instructions for Reynolds to give the envelope to Richard. Reynolds did not testify.
 Jessica stated that she opened the envelope because she thought the name "J. Jurzak" in the return address position referred to one of her relatives. After Jessica opened the envelope, she viewed the sexually explicit photographs. Jessica's mother, Heather Jurzak, contacted the police and the defendant was charged.
 After the presentation of the evidence, the trial judge stated that he believed Jessica's testimony and disbelieved the defendant's testimony regarding how the envelope came into Jessica's possession. The judge found the defendant guilty and imposed sentence. The defendant appealed.
 The defendant submits that the State failed to prove the elements of the offense beyond a reasonable doubt. Specifically, she contends that the State failed to prove that she had the requisite mental state to commit the crime.
 When analyzing the sufficiency of the evidence, we review the evidence in the light most favorable to the prosecution and consider whether any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt. People v. Barham, 337 Ill. App. 3d 1121, 788 N.E.2d 297 (2003).
 The offense of distribution of harmful material to a minor contains the following elements: "A person who *** knowingly distributes *** any harmful material to a child, is guilty" of the offense. 720 ILCS 5/11-21(a) (West 2000). "Distribute means to transfer possession ***." 720 ILCS 5/11--21(b)(3) (West 2000). "Knowingly, as used in this section[,] means having knowledge of the contents of the subject matter ***." 720 ILCS 5/11--21(b)(4) (West 2000). ...