I noticed, in the b/w shot of her baby's christening, you could see Count Flemming of Rosenborg in the background. Also, it's Margarethe of Sweden meeting Elvis, not Birgitta. The princesses were doing a promotional tour of the US on behalf of SAS. There's another photo series of them at Disneyland, riding the Teacups, all dressed up. Very cute.
You are correct it is Margaretha. I have noticed the mistake in another post about Birgitta/Margaretha. But I wasn't able to change it anymore over here.