Yes, but why is swearing unacceptable? Why is answering back not acceptable? Your 10 year old only has 10 years of life experience. Think about that for a moment.
Guide her and teach her. She’s still learning just like everyone else. Just like you are too. No one is perfectly behaved all the time.
You want her to budget her pocket money better. So, sit down with her and teach her, give her the skills to do that.
Some people who want to buy something expensive or outside of their budget actually do stuff to earn extra money. Maybe they do overtime or take on some extra jobs temporarily. That’s being proactive. A pp suggested that an alternative to just saying no was to offer extra jobs to earn extra pocket money. That’s a great idea if you have enough money to spare. If you don’t have the extra money, explain that.
You don’t want her calling people hurtful names or swearing. Teach her empathy. Ask her how would she feel if someone she loved called her a stupid bitch. That’s how you have made me feel and it’s not ok.
And I understand wanting to dig your heels in when you feel like you’re being criticised and judged.
But really, people on this thread were just offering alternative views and advice. Then became concerned by your responses. I don’t think anyone on here is trying to judge you.
It’s up to you whether or not you take it on board. But at least give it some consideration.