Why do girls take forever to txt back?

I just met this girls and we've been texting a little, but whenever I text her she takes anywhere from 20 minutes to 2 hours to get back to me. The most annoying part is i have an iPhone and it tells me when my texts have been read and they'll show up read like 2 minutes after I text her so I know she saw it but then she still gets back to me later. She almost always ends her texts with:) and calls me sweetheart a lot. What the hell is happening haha? Thanks for ur answers in advance!

She's probably also interested in other guys other than you.

It's possible that she is very busy. Also, she's probably ending her texts like that to show that she's interested in talking to you, but is busy at the time. Depending on the length of her response texts, it could be a combination of being a slow typer and being busy

Not everyone lives on their phone every minute?