ISO BFamily Born 4-10-1972

I was just curious if you have ever located your birth family? I am in search of information on a sister. My mother had a child in either 71-72 but I have been told most likely 72 and in the spring and she had her at Lancaster General Hospital. My mothers name at the time was Joan Blevins. You just happen to fit into my search criteria and am sending this in hopes of more information. It is so hard to search when you have very little to go on. My mother and grandmother have passed away and I only found out about his after the fact. If you have any tips on finding family I would greatly appreciate it.