Lena was a friend of Sheila Jackson who appeared throughout Series 2 and began a relationship with Lip Gallagher. Lena had asked Sheila to look after her pets while she was away but due to being busy one day, she asked Lip to do it instead.
Lip had been struggling to find quiet to finish homework so found Lena's house a haven, but he didn't take advantage and left money for any phone calls he used and kept the place tidy. However going there one night he found the house dark and trashed, picking his way through the mess he was suddenly jumped by Lena who though he had broken in. The police were called and Lip was taken into custody after trying to escape and hitting an officer.
It was discovered that Carl and one of his friends had taken Lena's keys from Sheila's and a group of bullies had turned up and trashed the place. Marty, Ian and Carl were forced to steal back Lena's belongings from the bullies while Fiona appealed to Lena to drop the charges.
Lip was eventually released and went to Lena to apologize for everything but they suddenly started kissing and went on to have sex. They began a sexual relationship that continued throughout the series, with Lena even driving Lip to school some days. This annoyed Fiona one day however and she confronted Lena for sleeping with a 16 year old boy and buying him clothes and haircuts. Lena wasn't bothered though and simply pointed out that it was legal.