Or maybe this could even be [Mandarin > Shanghainese] but not really?

I have two sisters from Shanghai (middle aged in the early 00s) who live in different Western countries. For reader purposes I want to add a little Shanghainese without the conversation being in the language.

I need a vibe check. I know enough Mandarin to get in trouble, so I was legit on a Mandarin -> Shanghainese dictionary, but I know that's not enough for what I'm doing. There's gonna be cultural stuff a dictionary doesn't explain.

This is my attempt. The English parts, I want to stay English, so I need to know only if the Shanghainese sounds right:

A: Ue? (Hello)

B: Hello, Me-me.

C: Oh, Jiajia aa. (Oh, Older Sister!) How are things?

That's it. 喂 -> Ue, 妹妹 -> Meme, 姐姐 -> Jiajia, and after reading a whole linguistics dissertation on sentence-ending particles in Shanghainese, I've come up with "aa3" for the equivalent of Mandarin 啊 that's like softening a statement, making it more colloquial, etc.

Help?