Singer Ashlee Simpson has advised young couples against getting wed too soon, after watching her sister Jessica Simpson's marriage to husband Nick Lachey collapse. Simpson and Lachey married when she was just 22-years-old and Ashlee is convinced people in their twenties are not mature enough to make such a serious commitment. She explains, "I've watched Jessica go through a really hard time (in her divorce). Marriage is definitely not on my mind. "Sometimes things don't work out the way you thought they would. I'm absolutely in love and in a committed relationship, but we live day-to-day. "There's a lot of growing up you do in your twenties, and I definitely want to wait until my late twenties or early thirties or whenever the time is right."