Can I just start by saying, I don't sew. I can barely hem my own pants.

I bought a dress off eBay last week to wear to a Hen's party this weekend. I tried it on last night and it's a size too big. My DSD1 stood behind me and pulled it in so it bunched at the back, so I'm wondering if there's a quick and easy way I can pin the dress?

I don't own a sewing maching so can I do this by hand? Or would I be able to even do it using safety pins?

Thanks in advance

Nic xo