I think it would be fun to read the dialogue with the lisps, lol. In reality, I believe they tell you she has this.

Good question. I guess in narration the author could mention the lisp, and then later in quotation the author could note, "she lisped." For instance: The evening air was still enough so that Karen could easily here Michael's lisp as they spoke by the shore. "It's so nice to be out here with you, Mickey. I feel lucky to be the one, " said Karen. "It's I who should say lucky," lisped Michael. What do you think? Looks OK to me, at least it'd work.

First of all, you have to decide *why* she is lisping. Nothing in a novel should happen at random. If someone has a particular characteristic, then that characteristic has to tell us something about them, or how they are perceived by others. So in that position I would not adopt either of the alternatives you give, but would give other people's reactions to her lisp.

That would depend on whether she were a lithe character.

Thith ith an interethting quethtion! My anthwer ith worth pointh yeth!!

Just say, "She lisped." Otherwise, the reader will have a hard time reading that character's dialogue. Emily Bronte did that with a character from Heathcliff, and I just ended up skipping over his portions of dialogue because I had nooo idea what was being said!

I would probably find it both appropraite and entertaining, it would be like watching a play.

Great question...I ran into that with some dialog in Dante's Secret...because it is set in the late Middle ages.... To write all of the dialog in exact language...could be a challenge for the reader...(and in some cases not fully appropriate since the spoken words may in many cases have SOUNDED not that different from today's use sound of the same words...) The WRITTEN WORDS were where the real differences took place! I think it would be better to have SOME of the dialog reflect the lisp...but not throughout the entire portion of the character's speaking... By the same token...to have to write and read..."he lisped" fifty or a hundred times throughout the story, if this fellow has a lot to say...is going to become horribly and boringly repetitive... You'll have to get creative! It's like writing in the first person for your main character....GOD FORBID you start all, or a large number, of sentences with "I" that SO doesn't work! If writing in the first person (the main character or one of the main characters is telling the tale...) you HAVE GOT to figure out how to allow them to tell the story WITHOUT excessive "I, I, I!"

I don't know, the phrase "she lisped" tagged onto every sentence just sounds weird to me. You could just mention she had a lisp, and maybe hae other characters comment on it. You could always spell it out (I tend to favor that), especially if she's a minor character who doesn't speak too often. The downside would be that it could turn into something of a joke. Terry Pratchett does this with his characters named Igor (one of which had a dog named Thcrapth) and it's a running joke throughout the series.

Most people with lisps avoid words that use the letter s. . A lot(most) of people with that problem(lisps) avoid language(words) that require(use) that letter(s). . So you could have the main character with a lisp and no one would even know it until the end of the book, when she finally slips up.