Hmm in terms of having kids pretty much off the bat, I’d say Maria and Anna Dorothea are at the top of the list. Anna Sophie would be a decent shohld for a prestigious kingly Protestant marriage but her young age does somewhat discount her I think
Of these, she and Maria of Nassau come with the best dowry (Maria's one including write off of Stuarts' debts during Interregnum).
Sound like Maria of Nassau is a much stronger candidate than I though and our Queen to be as Luise Marie is Catholic (and Henry would marry Catarina instead of her)Re. Henry IX, he either goes for Maria to settle dowry issue his sister's protests nonwithstanding, or honor the offer of Prince Conde and marry a cousin who Conde proposed him to marry while in France.
Given how stubborn Stuart brothers were sometimes when it came to decisions, both are likely.
Then she could very well end in Vienna, considering the situation in Portugal… and if she end in Vienna under suggestions of Rupert, Mary could drop her objections to Maria for Henry, if that match come with benefit for her about her son’s guardianshipRupert and Archduke Leopold lobbied the Austrian match for her as for a time it was not clear Felipe IV would leave thriving male issue, and as Spanish-Austrian PU was undesirable, it was lobbied that the young Emperor marries anybody else than heiress presumptive.