[2] She was born on July 10, 1938, in Brooklyn, New York, to Ruth Frankel and M. Stanley Metz.

[3][4] She graduated from the University of Massachusetts Amherst with a Bachelor of Arts degree in Sociology in 1960, Newton College with a Master of Education degree in 1972, and from Boston College Law School with a Juris Doctor in 1987.

[2] In 1998, Sydney defeated 14-term incumbent John Businger in the Democratic primary for the 15th Norfolk District House seat by 35 votes.

[8] In 2000, Sydney lost to Brookline School Committee member Frank Smizik 2,517 votes to 2,336.

[9] Between 2017 and 2018 she served as an area leader for the Broward County Democratic Party representing Coconut Creek and Margate in Florida.