2005: She was October on FHM magazine's 2005 pin-up calendar.

Katherine has the same birthday as her former "Roswell" (1999) co-star Colin Hanks.

Was with the Elite Modelling Agency.

Ranked #72 in Stuff magazine's "102 Sexiest Women In The World" (2002)

2005: Ranked as #55 in FHM`s "100 Sexiest Women in the World 2005" special supplement.

2007: Plans to marry fiancé Josh Kelley, on December 23, 2007 in Utah where she has a ranch property. There will be a tribute to her late brother, Jason, at the ceremony [July 18, 2007].

2001: Cut & dyed her hair for season 3 of "Roswell" (1999).

1996: Graduated from New Canaan High School.

2006: Named #19 in FHM magazine's "100 Sexiest Women in the World 2006" supplement.

She played the cello in High School.

1994: Began dating Joseph Lawrence. They met at Seventeen Magazine`s 50th Anniversary party.

2006 June: Engaged to musician Josh Kelley.

2007: Was named one of Entertainment Weekly`s Top 25 Entertainers Of The Year.

Auditioned for the role of Felicity Porter in the TV series "Felicity" (1998), but lost out to Keri Russell. She also auditioned for the roles of Sydney Bristow and Lauren Reed on "Alias" (2001), but lost out to Jennifer Garner and Melissa George, respectively.

Katherine is related to actress Amber Perkins.

Best friend of her "Grey`s Anatomy" (2005) co-star T.R. Knight, who was a groomsman at her wedding.

2007: Was writer/director Judd Apatow`s first choice for the lead role in Knocked Up (2007).

2007: Ranked #14 on the Maxim magazine Hot 100 of 2007 list.

In Judd Apatow`s film, The 40 Year Old Virgin (2005), the FHM "100 Sexiest Women in the World 2005" special supplement with Katherine on the cover is shown in close-up during a scene on the extended version DVD. Katherine plays the lead in Apatow`s follow-up, Knocked Up (2007).

Katherine has played a character with the name of "Isabel/Isobel" three times. "Grey`s Anatomy" (2005), "Roswell" (1999) and Wuthering Heights (2003) (TV).

Her last name is pronounced "HI guhl."

1994: Beat out Alicia Silverstone for the lead role in My Father the Hero (1994).

She is half Irish and half German.

1999: Auditioned for all 3 female leads on "Roswell" (1999) before being cast as Isabel.

Has two older brothers, Holt and John; and older sister, Meg. Brother Jason died from head injuries suffered in a car accident when she was very young.