I don't think she's had surgery. I had an enlargement years ago though. I needed it bad as I had very small breasts or "Two paracetamols on an ironing board" as my mother used to say.
Luckily, I had a naturally ample rack, but boob jobs were really difficult to get and have done right in the 1930s-1950s. Sometime I wish for those old days, because half of the "new Hollywood trash" wouldn't be able to get work if it hadn't been for their boob jobs and we'd have some real talent around today, as opposed to walking silicone Bevery Hills science projects.