Ru never misses a hot party!

Rumer Willis hit up the Nylon Young Hollywood Issue party at the Roosevelt Hotel last night, and we love her understated all black ensemble! Some celebrities try too hard with their fashions, but Bruce and Demi's eldest daughter always manages to effortlessly nail the right look!

We wonder if she got a dog sitter for her night on the town? Miss Willis recently adopted this adorable puppy from an LA animal shelter... aww, what a cutie! Fun fact - the pooch is Miley Cyrus' dog Happy's sibling.

See who the curly haired redhead was spotted partying with after the jump...

She's got her "smart" glasses on, so it must be important!

Rumer Willis stepped out looking 80s-chic in high-waisted jeans, plain white tee, a black cardigan sweater, bright red messenger bag and Wayfarer Ray-Ban specs, as she hurried to a meeting next to the Byron and Tracey salon in Beverly Hills, on Saturday afternoon.

The eldest daughter of Bruce Willis and Demi Moore has had a bit of a stressful year this far, with her mom rushing to rehab after her divorce from Ashton Kutcher, and dad recently welcoming a baby girl with new wife Emma Heming, but "The Rue" appears to he taking it in stride.

We admire the 23-year-old for handling the stressful pressure with such grace!

Aww, it's so good to see her smile!

Rumer Willis was snapped with a girlfriend at Bagatelle in West Hollywood last night for the Black November screening, and she kept it simple with skinny jeans, a button down shirt and a dark blazer. Rumer recently chatted with People about her style, and she insists that she's not on top of the latest trends. "One day I will walk out of the house in a dress and a pair of cowboy boots, the next day I'll have a pair of black jeans and a vintage T-shirt," she said. "[My style] changes … I'm not trying to look fashionable all the time."

So what about her scarlet locks? "I think I've finally settled into something that I like a lot. I love being a redhead. It's really fun!"

Talk about some fierce faces!

Yesterday we spotted Tallulah and Rumer Willis out and about in Los Angeles, and it looks like they had NO idea there were supposed to be torrential downpours all day. C'mon ladies -- check the weather reports! Then you wouldn't have gotten soaking wet and looked like this while running back to your car without an umbrella!

Rumer Willis wore a comfy sweater and baggy pants while out on a coffee run in Los Angeles, but we couldn't help but notice the name on her cup. I guess the name "Ruby" will do!

Demi Moore and Bruce Willis' oldest daughter, wearing dark hipster glasses, is still rockin' that fiery red mane. Maybe that's where she got the inspiration for her cute nickname.

Just two weeks ago, Rumer became an older sister once again when her dad and his wife Emma Heming welcomed newborn baby girl Mabel Ray Willis.

Perhaps Ruby Rumer has been staying up late with her new sister and needed a jolt of caffeine. We have to admit, we're lovin' her casual style!

Rumer Willis has been focused on keeping her friendships a priority ever since her mom, Demi Moore, was hospitalized back on January 23 after overdosing on cans of nitris oxide.

The 23-year-old singer ... sporting wavy red hair, basic jeans and black flats, left a friends house in LA with a notebook in hand. Perhaps she's penning some new songs?

Pretty soon, Rumer will be a big sister again. Her dad, Bruce, is expecting a baby soon with his 33-year-old wife Emma Hemming!

Ouch! Looks like Rumer Willis hasn't been too friendly to her knees.

Demi Moore and Bruce Willis' daughter made a pit stop at a Hollywood gas station with a gal pal wearing a long and loose trench, cut-off jean shorts, brown cowboy boots ... and some majorly bruised knee caps.

The 23-year-old starlet has had quite the week. On Monday, she was promoting her film The Diary of Preston Plummer in Miami. Then on Tuesday night, she performed four songs at The Sayers Club in Hollywood ... with stepdad Ashton Kutcher in the audience cheering her on.

Never a dull moment for Ms. Willis!

Rumer Willis is a triple threat ... model, actress AND singer!

Last night, Demi Moore and Bruce Willis' daughter hit the stage at Hollywood's The Sayers Club to sing four songs, and her stepdad Ashton Kutcher was in the crowd cheering her on.

The 23-year-old actress performed the following songs: "(Sittin' On) The Dock of the Bay", "I Can't Stand the Rain", "High Low Middle" and "Age."

Although Demi's ex kept a low profile during the performance, those inside the club say the Two and a Half Men actor took pics with his cell phone.

Too bad Rumer's mom couldn't be there. Then again, wonder if that would be awkward?

See the two leaving the club in our gallery below.