Think of all the recipes she would be trying!

I was gonna go with Ariel, but I think what with Elsa's social anxiety she would be more likely to get addicted to an alternate reality.

Rapunzel has the most free time, by far. :)

^Agreed.

Or Rapunzel. Anna has just as much free time as Rapunzel, so no Rapunzel does not have the most free time "by far".

^ Somehow I forgot about Anna. I'll put it this way: Rapunzel tries to fill her free time more than anyone else by far, since she has so many hobbies. I could easily see her getting engrossed in the internet, even moreso than other DPs with free time, like Anna.

or Anna

She's obsessed with human things...sooo...

Totally agree with what anaswill said about Elsa... Rapunzel and Anna might seem like it because of their isolation, but I can't see either of them being able to sit still long enough to develop an addiction.

I can see this. She'd be able to express herself online.
Maybe Ariel as well.

She and Rapunzel will took some selfies/

I think Ariel would be too busy out enjoying herself but Rapunzel would love socializing online. She'd love this site, I think.