it's not safe if you have the tray off and her not buckled in. the same with the bumbo chair, they recalled it a couple years ago because it didn't have a way to strap them in.
I think I got it when she was almost 4 months and kept trying off and on until she was 7 months or so. I would try to give her other toys to play with, but she wasn't having it. But maybe your baby would like it.
I had a similar one for my daughter, and honestly I really never used it. I put her in there sometimes for 15-20 min or so to do a quick chore, but she didn't really like it to much.