1923 Adoptee rights

My mother was raised by her birthmother and thought that the father that raised her was her true father. She found out approx. 20 years ago, that the father that raised her was her adoptive father. Her mother refused to share any information with her about her natural father. She did figure out that the father that raised her met and married her mother when she was around 2. My grandmother evidently then had her new husband adopt her and her original birth certificate was sealed. How wouuld my mother go about unsealing her birth certificate - she is 79 years old. She would like to do something to resolve this mystery for her - the state is Massachusetts. She also believes whe was baptised in the Catholic Church under her birth name - but does not know where to begin. Any advice?