Looking for 2 half sisters and 1 brother born at misercordia in early 1960's

My mother's madien name is Loux. She told me that she had two daughters and a son before she married. She was sent to misercordia to have all the children. She was 14,16 and 18 when she had these children. Some of the birth names I can remember is Elizabeth Ann and Brian James. Sorry I don't rember the third name. All the children were born in the early 1960's and birthdays are in March and April.