She also played Belle in the Dutch musical production of Beauty and the Beast (noted for being the first Belle with blonde hair) and Jane in Tarzan. From late 2011 to mid 2012, she starred as Glinda in the musical Wicked. She also sang a song against cancer, called "Vecht Mee" (English: Fight With Us) with Dutch rapper Yes-R. Internationally, she's best known for co-hosting Eurovision: Europe Shine a Light and the Eurovision Song Contest 2021.
Janzen won the John Kraaijkamp Musical Award [nl] in 2002 for Upcoming Talent for her lead in Saturday Night Fever. She also won a musical award in 2005 for Best actress in a supporting role for the musical Crazy For You. She got nominated for Best female lead in 2006 as Belle in Beauty and the Beast and in 2007 she got nominated for the same prize for her role as Jane in the musical Tarzan. Because of her pregnancy she had to temporarily leave her part in the musical Tarzan from September 2008 through April 2009. She was replaced by Bente van den Brand. After Tarzan she played a part in the Disney Musical Sing-Along.[7] In 2010 Janzen can be seen in the musical Petticoat. It's an original Dutch musical, written especially for her. After her role in Petticoat she played the role of Glinda in the Dutch rendition of the Broadway musical Wicked.[8]
In 2011 Janzen ended her contract with the Dutch TV channel AVRO and signed a contract with RTL. According to her, hosting the award shows she had been hosting at the AVRO for the fourth year in a row, would make her performance look cheap. She was enthused by the idea of experiencing other things.[9] In 2012 Janzen had roles in the series Divorce and Goede tijden, slechte tijden.[10] Later on in 2019 Janzen returned in another small role in Goede tijden, slechte tijden.[11]
Janzen is in a relationship with Marco Geeratz. She gave birth to their first son, James, on 23 January 2009. On 15 December 2014, they were married in London. Geeratz has three children from a prior relationship.[7] On 30 March 2018, the couple had their second son, Bobby.[24]