Complex sentence: She started her solo career in 2003, when she had part in Melodifestivalen 2003 with the song "Mr. Memory", but she ends 6th in her semifinal losing the chance to qualify for the final.
Split into simpler sentences: She started her solo career in 2003, when she took part in Melodifestivalen 2003 with the song "Mr. Memory". However, she finished 6th in her semifinal, and thus lost the chance to qualify for the final.