Flame Retardant Fabric?

I am finally in the process of knitting my baby’s blanket. First blanket for me! I decided to add a lining to it and I’ve found some very cute, retro fabrics. Unfortunately, all the ones I’m coming across aren’t flame retardant. Does anyone know of a place that sells cute FLAME RETARDANT fabrics online?

I don’t know of any flame retardant yarns thats aren’t commercial grade. However, acrylic tends to melt instead of burn.

Wool is naturally flame retardant. However, for little ones you have to be careful of allergies.

I think lining it would make it way too warm.