Okay… I just had this weird brain storm head canon moment…
Remember how before Daring Doo was confirmed for "real" in verse, we kind of assumed that Twilight's mom wrote the Daring Doo series?
Well… I'm suddenly thinking… What if there's two versions of Daring Doo? Similar to James Bond being a legacy character.
To put it another way… What if it turns out the Daring Doo series has been going on long enough that the original writer of Daring Doo had retired and left the work to someone else? Perhaps having written the original series long enough ago that the books didn't have illustrated covers?
In that sense… The following reasoning is that if one Daring Doo is real, and writes stories of her own life, then the hypothetical other Daring Doo might exist as well.
Of course, writing this I realize the next thought implied is "Twilight's mom is Daring Doo"… Except that would be wrong, since Twilight's Mom is a Unicorn, not a Pegasus. So with that in mind here's my thoughts…
Perhaps Twilight's Mom was a friend, or maybe sister to the original Daring Doo, and when the original Daring Doo came back from adventures, Twilight's mom would novelize the account for publishing; presumably cause the first Daring Doo wasn't much of a writer.
… Later, the original Daring Doo would have a child that would continue the legacy, while deciding to novelize the series herself. Thus closing the comic/cartoon plot hole.
Of course… If you take the idea that the original Daring Doo is Twilight's Mom's sister seriously… That also would also get the idea that the current Daring Doo is Twilight Sparkle's cousin.
So yeah… This shall be my head canon, as complicated as it is.