A rainbow budgie is a composite mix of yellow face type2, clearwing and opaline in a blue series bird. Does your rainbow has these mutations ?
Whatever it is, when one parent is a DF spangle mates with a non-spangle, all chicks will be 100% spangle. However the chicks will also be split for other mutations depending on the sex-linked (opaline for example) or non-sex-linked mutations (clearwing for example).
The parents are both spangles, and not a rainbow hen. In fact, your hen is a yellow face type 2 cobalt spangle.
DF spangle cock mates with a YF type2 spangle hen will produce 50% double factor spangles and 50% single factor spangle. If the cock is not split for blue, you will get 100% green series chicks, meaning DF yellow spangles (just like the dad) and SF spangles of lightgreen, darkgreen and maybe olives depending on the dark factor of the cock.