Gentle parenting doesn't mean no boundaries and no consequences. I am sure you know that already, but it doesn't appear that your daughter does.

I gentle parent my 4.5yo and he thrives on it. If he tantrums I just remind him I can't understand him when he speaks like that. If he's really upset I sympathise, but can't help until he asks so I can understand. I cannot understand impolite sentences, so I do select what I can and cannot understand. Slamming doors would result in having to come back and practice closing doors properly, for example.

I talk to my son as if he were capable of understanding things - and he usually rises to the challenge. We talk about what behaviour we enjoy and what we don't. I make a big fuss of him when he behaves in the mutually agreed way - and sympathise when someone else is "naughty" on his scale of things. I also ask him if his rules are fair: if snatching is fair, is it OK for me to snatch off Liebling? No? OK, snatching isn't fair at all then.

For a pre-school boy, he is amazingly empathic, sensitive, kind and loving. He isn't perfect, but he knows if he's doing wrong and is confident enough to tell me off when I do things wrong.