Breast Augmentation with Minimal Natural Breast Tissue?

My fiance is Asian and has little or no breast tissue. She wears a bra that is essentially all foam, as there is no need to wear one. She is very self-conscious about it and wants to have breast implants. I am concerned that with so little natural tissue that it would not look right, and she might be even more self-conscious. Would breast implants look natural on a woman with little or no natural tissue, and if so, how much enhancement could she expect ? She is very thin with very tight skin.