Jamie Lynn Spears took a hard pass on doing a nationwide tour to promote her new book ...

They won't say which charities because Jamie Lynn tried to donate profits from the book to a charity last October, but the charity rejected her gesture because of all the backlash.

So, our sources say Jamie Lynn doesn't want to name the charities this time around, to avoid a similar outcome.

While Jamie Lynn did a couple of media interviews about the book, we're told she doesn't feel like it's necessary to go further with a tour ...