As an editor, I'm always on the lookout for weak words. Some words we use just don't pull their weight. As an extreme example, consider "thing." "She picked up a thing" tells us almost nothing. Was it a knife? An octopus? In fact, when someone uses the word "thing," we might suspect them of being intentionally vague. "What did you do last night?" "Oh, not much. Took care of some things." Things, huh? Sounds sketchy.
A delightfully vague word that absolutely does pull its weight, at least in dialogue, is "nice." A character over the age of six describing someone as nice is up to something with their choice of word. A man comes home and describes his date to his roommate. "She was nice." Nice? That's it? Nice, while being vague, opens up a world of possibilities when it comes to our character. Was he bored by her? Was she so wonderful he doesn't want to say anything more and risk gushing about her? Did she stand him up and he's too embarrassed to tell his roommate?
Interestingly, this ambiguity is built in to nice's etymology. It comes to us from a twelfth-century French word (also nice, but ... you know, pronounced different), which meant "careless, clumsy, and weak" and which came itself from Latin nescius, meaning "ignorant" (literally, not-knowing). Over time, nice evolved through meaning timid, fussy, fastidious, precise, and agreeable before finally settling on our current definition: kind and considerate.
This particular path, from negative to positive, from vague to precise and back again, makes nice a workhorse of a word in the right character's mouth. Use it to show what she doesn't want to say, or what she can't say, or the only thing she can say without saying something else. It's a subtle little drop of uncertainty to add a bit of tension to your story.
Have a nice day! Really, I mean it!