"I rhyme with tyre - And cause pollution - I think you'll find - It's the best solution: What Am I?"
"And that's the essential problem with 'Planetary' right there. When Elijah Snow says, 'The world is a strange place'... he gets Dracula, Doc Savage and Godzilla... When we say it, we get The Captain Fire-Cock Rock 'n' Roll Spectacular."
~ Pól Rua
When Brunhilde was "created" by the Enchantress, she was Amora's plaything. Then, Amora empowered Barabara Norriss with the Valkyrie's essence to free herself, the Executioner and their erstwhile allies, the Defenders, from the clutches of the sorceress Cassiolena. After that, Valkyrie stayed with the Defenders for years.
The Thor cameos were just brief background showings. After all, Brunhilde is an Asgardian demigoddess.
^This.^ However, The Valkyrie is, and yet is not a team created character.
Valkyrie was a disguise The Enchantress adopted to turn the female Avengers against their comrades as Lady Liberators. However, she imposed that persona on the insane Barbara Norris in The Defenders. Both The Enchantress and Barbara Norris were created outside teams.
So created for a team? Yes-ish. Created as part of a team (in either form)....? Bit more complicated.
Overall, I'd say yah. Team creation.