We used dr browns 4oz glass bottles for a while on our youngest. She held them just fine but I actually dropped one though lol. Now when she got older we switched to a different brand. As long as you have a good understanding behind your decisions do exactly how you please.
There's nothing wrong with glass. My mum said she used them with me and if they were easy to find over here and cheaper, I would've too. Just don't let baby hold it themselves and there's no risk of them dropping it. Tell her to mind her own.
My babies always held them with no issues, it was my own fault for leaving it around him after it was empty but I love them so much more than our plastic ones.
Our first one broke today baby #2, 8 months old, my daughter used the same ones he’s using now. And yes seriously thank you. I didn’t want to make a fuss in front of my MIL and the restaurant but I literally wanted to say shut up.