help taming

Hi there! So, I'm a new owner of a 7 month old Indian ringneck who I named Chartreuse. They were handfed as a baby but wasn't touched much afterwards. I'm not entirely new to bird, I had a couple of love birds, and my beloved Sun Conure who had complications with epilepsy and passed a while...

So, a month or so ago, I got a lovebird. The internet told me to get a younger lovebird, so I figured 5 months was young enough. I was wrong. I don't want to regret buying her, however, and have tried to tame her. It doesn't work. TL;DR: any advice on taming a non-hand fed, 5-month-old, female...