Regarding the Chinese brands, you're probably thinking about Xiaomi, OPPO, or the Taiwanese brand whose name escapes my mind at the moment (Huawei maybe?).
However, if you allow your kid to take a smartphone to bed, you may be opening up yourself to power struggles in the future. A smartphone means texting, Facetiming, Facebooking, Skyping, Snapchatting, Twittering, What's Apping, Pinteresting, YouTubing, gaming, etc. in bed. She needs a music-playing device for bedtime; it doesn't sound like she needs the camera, browsing, and YouTube functions you mentioned when she is in bed. Besides, the glare from the screen itself is not conducive to sleep, which is why those who teach sleep hygiene recommend that all screens are turned off at least an hour before bedtime, especially for people who are already dealing with insomnia.
If the only purpose for having a phone in bed is to listen to music, why not just buy an mp3 player such as an iPod? The point is what she uses in bed to listen to music should be separate from what she uses during the day for browsing and taking pictures.