Sometimes in my writing I overuse only. Usually when I’m trying to emphasize and idea or word. Here are my examples from The Proper Way to Say Goodbye, where I deleted the onlys.
-Like I said, he only referred to her as Dent’s daughter
-Sucks cause she’s only nineteen and can’t go to the bars.
-I only went to get a drink.
Another thing I looked at was using only vs. just. Sometimes just sounds better, so Chloe does use it. But otherwise, when either works, I used only for her to distinguish her voice. And just for the others.
-Chloe: Wait, you kissed her. Like after only two dates?
(Previously, it was, “Like after just two dates?”)
-Murphy: They just use Charles when they’re mad.
(Previously, it was, “The only time they use Charles is when they’re mad.”)
So only is a good word to use to differentiate your voices. And make sure you’re not overusing it like I was.