Name for angel baby

I lost a baby due to miscarriage last year at 15 weeks and therefore never was able to find out the gender. I didn’t name that baby but I feel like I want to because I want to honor them and I want to be able to refer to them as not just my angel baby. It would just be for me, my husband doesn’t talk about that baby at all.

We had our rainbow baby in January and I want her to eventually know about her angel sibling when she’s older.

Can anyone suggests gender neutral names for my angle baby?

Thank you