I think you can support her even if she’s terrible. I was told I had a bad voice when my dad took me to a singing teacher at the age of 5. But, I didn’t stop singing. I kept singing. But my voice improved overtime. I am pretty decent now singing certain songs in Karaoke. But, I think I could’ve really given singing a try if my parents supported me a bit more in that area. My voice also changed as an adult. It sounds better now. I learned to sing from my diaphram. So, you never know. It’s all in the practice. I love it that your daughter found something she loves to do.