Trivia

She was scheduled to be at a meeting on the 15th floor of the World Trade Center on September 11, 2001, shortly after the attacks occurred, but she overslept.

She is not the mother of Gaten Matarazzo, whose mother is also named Heather.

Heather wrote an article on her blog entitled 'What the fuck is fuckable' on 6th February 2015, which was in turn featured on Huffington Post on 7th April 2016. The article addressed the issue of beauty and looks in the film industry which arose from an incident where Heather was fired from a movie just 2 weeks before filming began despite having stayed committed to the project for 2 years. The director broke the news to her and said her firing was the producers' decision, citing her as not being 'fuckable' for the movie. Heather used the article to vehemently protest against Charlize Theron's claims that she (Theron) had been passed up for roles because of her looks in an interview entitled 'Pretty People Get Turned Away First For Serious Roles' for British GQ magazine for their April 2016 issue.

She is of completely Irish descent and was adopted by an Italian-American family, hence her surname.

She Became great friends with Anne Hathaway during the shooting of The Princess Diaries (2001). They still call each other frequently and hope to be friends for the rest of their lives.

Won the Independent Spirit Award for Best Debut Performance for her starring role in Welcome to the Dollhouse (1995).

In April 2005, she was the keynote speaker at the Gay, Lesbian and Straight Education Network of Boston's 15th annual conference, at Brookline High School, where she described her struggle to gain acceptance of her sexuality. "It was such a burden, because I had to pretend to be this person that I wasn't."

Turned down reprising the role of Dawn Wiener in Palindromes (2004).

She is Irish-American. Her biological father was from Knock in County Mayo, Ireland.

Attended BOCES Cultural Arts Center for musical theatre.

Her homemaker mom, Camille, and dad Ray - a data processor - live on Long Island.

Starring with Thaao Penghlis in the world premiere of "Class", by Charles Evered, at Cape May Stage in Cape May, NJ. (May 2010)

Heather flunked the written part of her driving test, missing 11 of 20 questions. (September 1999)

Attended a GLSEN conference as the keynote speaker in Brookline, Massachusetts. (April 2005)

Moving to Los Angeles (April 2002)

She is also Italian descendant.