SEARCHING FOR SISTER born 3/31/1961 st pete?

my sister (1/2 sister) that I am just finding out that I have was born 3/31/61 March 31, 1961 according to the birth mother. Birth Mother is named Lynn. She does not remember the hospital name and states was st. pete florida and did not list any father. The adoption was done via private lawyer. I would love any leads to find my sister. Thank you.