I don't know... when you're a bigger cup size like that it can be difficult to find lingerie that fits correctly, even if you know all of your measurements and are shopping for yourself. It may be a very tricky gift and you should probably be prepared to exchange it for a different size in the likelihood that she tries it on and it doesn't fit.

yeah she know i am getting it for her but its just hard to know what size because of of her bigger boobs

Sizes aren't really standardized between all companies, so I'd go with the sizing chart that is provided on all lingerie product pages to be sure, since it is company specific. Someone may usually wear Mediums when it comes to shirts, but when buying a piece of lingerie, they may actually need to buy a Large depending on how the company sizes their items.

If you really want to be safe, you could look for items with freer sizing, like babydolls that don't depend on her waist size, etc.

Look around for pieces that would fit her body as well as her breasts, like pieces that have more room in the breast area. What size is she in bottoms normally? I will help you look for something.

Babydolls are ideal! You only have to worry about one measurement--the bust--and they're very flattering for most body shapes.