Thank you for your inquiry.
About this bra, the cup is a little shallower than other bras, so one bigger cup size may fit you.
For female A, the normal size is B75, so we recommend B75 or C75 to her.
For female B, the normal size is B85, so we should recommend B85 or C85 to her, but unfortunately, this bra doesn't have the undersize 85, so it is difficult for me to recommend a suitable size to her.
Please note that it is only guide and the size depends on your figure, the material and the design of the item.
We hope this information helps you.
Thank you so much.