LOS ANGELES - Singer Ashlee Simpson says she wants to wait to get married ¡ª unlike her big sister Jessica.

The 21-year-old revealed in an interview with Teen People in its June/July edition that she has watched her newly single sister "go through a really hard time" and that tying the knot "is definitely not on my mind."

While Ashlee Simpson said she was "absolutely in love" with her band mate and boyfriend Braxton Olita, she added that she's taking it slow.

"There's a lot of growing you do in your 20s, and I definitely want to wait until my late 20s or 30s or whenever the time is right," she told the magazine.

Simpson's singer-actress sister Jessica, 25, filed for divorce in December from Nick Lachey after three years of marriage.

Ashlee Simpson does hope to follow in Jessica's footsteps in another way ¡ª acting.

"I'd like to do a really great movie by the time I'm 25," she said, adding that she was currently reading scripts and looking at films with a style like writer-director Quentin Tarantino's.

Her summer tour began Saturday in West Palm Beach, Fla.