Kendall Jenner may just be 19 years old, but the model and reality star looked mature beyond her years in Beverly Hills on Tuesday.

The Kardashians' little sister had an almost professional look when she was spotted walking and texting her way through the business district of the toney Los Angeles enclave.

Not as flashy as many of Kendall's recent runway looks, the neutral shades of her outfit instead gave her a trendy twist on classic style.

With her hair pulled back into a loose ponytail, it probably was not a formal outing for the young woman.

While large sunglasses hid most of Kendall's face, perfectly shaped eyebrows did peek out over top of the lenses, and the young lady's lips were a subtle pink shade.

Kendall chose a tight-fitting, long-sleeved, grey T-shirt with a mock turtleneck collar for her top.

That relatively plain article of clothing was glammed up with a knee-length beige vest worn overtop and left wide open in the front.

Skin-tight black trousers made of a leather-like material covered the high-fashion model's legs.

Shiny, black ankle boots and a black purse slung over Kendall's shoulder completed the look.

No jewellery other than a silver-coloured wristwatch was visible to accent the outfit.

This may have been one of the first times in several days that Kendall has had time for a casual stroll, thanks to a run of photo-shoots and parties over the past week.

She was a guest at the 21st birthday party for One Direction singer (and former Kendall boyfriend), Harry Styles on Saturday, mere hours after a Vogue photo-shoot with Gigi Hadid and Ansel Elgort.

Around that same time, Kendall hung out with Gigi and singers Cody Simpson and Justin Bieber - both boys posted Instagram pics of the group.

A Love magazine cover story featuring Kendall (with friend and fellow model Cara) came out on Monday, adding to the busy week.

The constant news speculation surrounding the Jenner-Kardashian clan has been in high gear lately as well, thanks to increasingly confirmed rumours that dad Bruce Jenner is transitioning to being a woman.

Despite the attention, Kendall is reportedly fine with the situation.

'[Bruce] is finally happy and his family is accepting of what he's doing,' an unnamed source told People.

There is no word yet on whether or not busy Kendall might appear in a rumoured E! reality series about her father's journey.

This is the similar style by Kendall Jenner.

T-shirt /Lalalilo(HERE), Coat /Lalalilo(HERE), Pants /Lalalilo(HERE)