Joséphine princesse de Leuchtemberg, queen of Sweden
Mary princess of Teck, queen of the UK
Interesting ... well now that you mention morganauts, the Battenberg princesses come to mind. Ena gecame the queen of Spain, while her cousin Louise became the queen of Sweden.
There actually was controversy over the latter, since at the time (1923) there were questions as to whether the bride was of sufficient rank. As such, legal experts had to stretch the case for Louise being not just some *private man's daughter*.
Ena, like May and Louise, could not have married King Alfonso XIII of Spain, but for her royal ancestry (75%).