Probably just pouting. I think a lot of "did they get lip injections" is someone holding their face a different way, if that makes sense. If you hold your lips in a permanent pout they're going to start looking fuller. Which would make sense, as she's growing from kid's show actress to model, losing weight, etc. Maybe just adopting a sultrier expression?Did she do something to her lips? She kinda looks like Angelina Jolie (facially) in this picture.