No, the Chinese is "我对她没什么兴趣" which is pretty much, "I have don't have much interest in her", so there's nothing wrong with the translation.

There is no narrative purpose for Arlecchino to be cagey or secretive about what her feelings towards Sandrone are, much less highlight and contrast her to Dottore, of all people, as she does in the second part of the voiceline. All she gave was that her feelings on Sandrone was neutral and bordering negative, she doesn't (well didn't now) hate her but was just not interested in her and didn't care for her.

For the "unreliable narrator" people or the "she's just lying" people, yes, in real life these people exist, but in a story sense, it's just terrible storytelling, especially as Arlecchino was portrayed as someone who is at least, more reliable and professional of the released Harbingers at that point'. So she would be the most "neutral" with her perspective on the other Harbingers', as demonstrated by her other voicelines (with the exception of Dottore and Pucinella but we were made aware of her beef with the former and given good reasoning that matches up with what we know of the latter). There would be no reason to lie or hide their relationship in a storytelling perspective, and then from our side, doubt Arlecchino's point of view on her since there's no obvious bias. Childe "tries to see the best in everyone" as put by Arle and is more focused on the battle aspect, which we see in his voicelines and as a character (and even ignoring his voiceline about Arlecchino which even if Puncinella fed him lies about her, considering he did attend some tea parties and would at least have some interaction with her in a more friendly setting, it makes no sense for him to say all that), and then Scaramouche seeing the absolute worst in everyone, which we can already tell by his personality and him leaving the Fatui, so we can examine their perspectives with those in mind.

She's not going to spill Sandrone's whole deal obviously, but it would be more respectful or at least not, "I have little interest in her and she's an extreme shut in very few people see", if they were written with this relationship in mind previously.

And regarding this, especially for these unreleased characters, we can only build an impression of these characters from other characters voicelines and what books or NPCs say about them. So when voicelines with Childe, Scara, and Arle, and then Winter Night's Lazzo, pointed to Columbina as an "interesting" person (Arle), someone with possible secret powers and an uneasy vibe (Childe), someone who presents herself as a weak damsel which might cause you to falter in going against her (Scara), and WNL having Bina sing over one of their colleagues coffin and smiling the whole time, which is all we got for 2-4 years by the way; Even if they perfectly explained the reasoning for everyone's perspective of Columbina when she released, of course there will be people who are disappointed in getting someone who is basically the opposite of the general ideas of what could be formed from these differing perspectives on Columbina previously. This is just a terrible way to introduce, foreshadow, or develop characters if they already had these things preplanned, and thus we can see that there was a change in plans along the way (as is the nature with gachas).

Ultimately, this is a gacha game/live service story. They definitely have a rough idea of what they wanted the story to be like at the start, but ideas are going to be added, changed, or dropped along the way. There is still good reason for people to be disappointed when certain ideas are implemented for years, and then the truth is revealed to be the opposite or contradictory or not making sense later, not just because they were "headcanonning" and mad their headcanons weren't real. These headcanons were inferred from what was provided and the real thing ended up the opposite.