Still not sure if I would prefer her using the terms 'boy'/'kiddo', but that's probably just because I'm used to seeing 'shounen' in this series already.
I think I like this group’s translations more. Her referring to herself as “big sis” and calling him “kiddo” makes it more obvious that she doesn’t see him in a romantic light(yet) and sees him as a little brother/nephew, which was revealed in the latest chapter.
@liquidsword we don’t know what she was going to say before shounen hung up, but she said he was like her nephew IN THE BEGINNING. Probably she would say that she now has feelings for him...
@Nicito I noticed she was going to say something before she hung up. IMO I don’t think she has feeling for him NOW, but she was going to say that she didn’t see him as a little brother/nephew anymore. I think she was going to say she saw him as a friend, or maybe something like that. I don’t think she’ll have feeling for him until he gets a little older, but of course I could be wrong.