Hello,Customer and thank you for asking your question on Just Answer.
If your mother refuses to share any information with you, it will be difficult to find your sibling, but it CAN be done.
However, it will take time and be a major undertaking. The hospital cannot share any information, so you will have to search public records.
The way to find this sibling is to go to the recorder's office for Dade County and search the birth records for 1955 and 1956. There is most likely a "vital statistics" department, and within it you will find birth records.
You begin searching the birth records, which are usually on microfilm or computer. You just tell the people at the office what year you want to search. You may have to go month-by-month. You can narrow down your search by looking first for birth names with a last name of Doster. Even though the baby's name might have been changed immediately after or shortly after birth, the original birth certificate might still be under Doster.
When you find a baby with the last name of Doster born during those years, you can then check to see if the birth was at Jackson Memorial Hospital. Then you can see if other information on that birth certificate matches what you know - such as your mother's whole name and her birth date.
If you find no babies born in that time period with the last name of Doster, the search becomes bigger. You then search for all babies born during those years at Jackson Memorial Hospital. This is more difficult. You will need to look at any birth certificates you find to see if you can locate your mother's name.
Once you have found the correct birth certificate, you will then have a very good start in finding where your sibling is now.
If you don't find any birth certificate, my only other suggestion would be to try to talk to your mother about this. Perhaps with some gentle and loving prodding, she may finally decide she can share more about it all with you. If you get nowhere with this, you may try finding out more from your father. He may know more that he hasn't told you yet.
I really hope your mother will help you by giving you some information. If not, and if your father doesn't know anything else about it, I wish you the best of luck in searching the public records. If you can find the right birth certificate, please let me know, and I will try to help you trace your sibling further so you can follow up with this as your heart desires.
I how this answers your question, as far as how to proceed with it all, but if not please let me know so I can help your further.