There are several other princesses who were also under discussion/consideration at various points:
1) Louisa Maria Therese Stuart, Princess Royal of England, only surviving daughter of James II and Mary Beatrice of Modena. The match was pursued enthusiastically from the Jacobite side, but Carl rebuffed it with his usual answer of 'not yet'.
2) Charlotte Sophie of Brunswick-Wolfenbuttel, second daughter of Ludwig Rudolf of Brunswick. Yes, she was OTL tsarevna as wife of Alexei Petrovich, but her father basically did a coin toss to see who he should ally with, Sweden or Russia. So for those of you who want a Habsburg match without the Habsburgs this could be the way to go, since her older sister was Empress.
3) Maria Casimiria Sobieska, eldest daughter of Jakub Ludwik Sobieski. She was offered by her father at some point in the early 1700s for Queen for Sweden, however, the lady was unwilling and entered a convent instead. She would've brought an impressive dowry with her for a for-all-intents-and-purposes commoner, but it would open up the probability of another Polish-Swedish union due to her having no brothers.
4) Maria Elisabeth of Holstein-Gottorp, youngest sister of Carl's OTL brother-in-law. The marriage was pushed by his grandmother at some point in the late '90s, but never came to fruition.
5) Sophie Hedevig of Denmark, daughter of the Danish king, pushed by Carl XI (AFAIK) out of memory for his wife. However, the match foundered on certain points in the marriage contract. There was a brief attempt to reconsider it during the Traventhal Treaty, but no dice. Other matches considered for this princess included her cousin, the Elector of Saxony and the Holy Roman Emperor Josef I.
Other possible wives worth mentioning:
1) Sophie Dorothea of Hannover
2) Luise Dorothea of Prussia
3) One of the prince of Nassau-Dietz' sisters (if a match with Holland is sought)
4) One of the princesses of Anhalt-Dessau (same reason as 3)