Okay so honestly I wouldn't go below 50€ 😅 The super cheap stuff from Amazon is often really... well, let's just say "musically challenging" haha. The thing is, if the ukulele sounds like a broken toy and the strings are super uncomfortable, you lose motivation pretty quick. Your daughter might end up thinking she's just bad at it, when really it's just the instrument.
I'd rather recommend something in the 70-100€ range, you get actual beginner ukuleles that are actually playable. Brands like Kala or Stagg have solid budget models that are available on Amazon too. They look better, sound way better and the build quality isn't terrible 😂 That's the sweet spot for me when you're not sure if it'll stay interesting long-term.
If she's actually into it after a couple months, she can always upgrade later. But those really cheap things under 50€ in my experience just end up in a drawer pretty quick, even if the beginner would actually have fun if the instrument wasn't so rubbish. Don't go too cheap, trust me 🎸