[Matlock]

Originally Posted by jlo mein

There's also a very big key to this speculation. Spoiler warning, maybe you haven't read this far in the books, I've just read it on a wiki page:

Spoiler!

The only two people to see Lyanna Stark before her death were Ned Stark and Howland Reed. Howland is speculated to be appearing soon, with many believing he will reveal Jon Snow is the son of Rhaegar and Lyanna.

Spoiler!

There is also another popular theory that you can google which states that Jon Snow is Meera Reed's twin. They are the children of Rhaegar and Lyanna. Howland and Ned Stark separated them for their own safety. The theory will also remind us how Jon Snow and Meera Reed have very similar features and are about the same age in the book and in the show.

Meera didn't die in the show, so I'm still wondering if this theory could be true.