Searching for Sister born in san antonio texas in 1969

My mom was 18 years old and was in the salvation army home for unwed mothers in san antonio texas. She does not remember the exact date of birth but thinks that her daughter was born june-17th-1969. I am searching for my sister who would be about 41-43 now. She named the baby Clair Ann Gehrke but does not know what her name is now. My mother does not know the name of hospital either. If any one has any information please let me know. I know I have very little information but Im doing what I can to get that information. THank you!