Sydney began acting at the age of eight in local theater in her hometown of Boulder, Colorado. She appeared in the television series Emergency, Drake & Josh, Oliver Beene, Masters of Horror, The Brotherhood of Poland, New Hampshire, Femme Fatales and Chemistry. She has also appeared in the Charles Band-directed films The Gingerdead Manitoba, Evil Bong, The Haunted Casino, Evil Bong 2: King Bong, Skull Heads and Evil Bong 3D: The Wrath of Bong.
Besides acting, Sydney along with her mother Marian Heymsfield created the company Zorbitz in 2003.
Through the Zorbitz company they sell a number of children"s products in which they donate a portion of each sale to charities worldwide. Their most notable product is the Zip-itz Zipper bracelet, which has been endorsed by a number of celebrities.