The white wines of Germany are its glory. There are a wide variety of grapes planted, many of them laboratory-developed hybrids and Riesling crosses like Müller-Thurgau, Ortega and Rieslaner, designed not so much with quality in mind, but simply to ripen to high sugar levels. Two of the most popular are:

Riesling:
Riesling is a white grape variety which originates in the Rhine region of Germany. Riesling is an aromatic grape variety displaying flowery, almost perfumed, aromas as well as high acidity. It is used to make dry, semi-sweet, sweet and sparkling white wines. Riesling wines are usually varietally pure and are seldom oaked. As of 2004, Riesling was estimated to be the world’s 20th most grown variety at 120,000 acres (with an increasing trend), but in terms of importance for quality wines, it is usually included in the “top three” white wine varieties together with Chardonnay and Sauvignon Blanc. Riesling is a variety which is highly “terroir-expressive”, meaning that the character of Riesling wines is clearly influenced by the wine’s place of origin.

In 2006, Riesling was the most grown variety in Germany with 20.8% and 52,380 acres, and in the French region of Alsace with 21.9% and 8,300 acres. There are also significant plantings of Riesling in Austria, northern Italy, Australia, New Zealand, United States, Canada, China and Ukraine. In the countries where it is cultivated, Riesling is most commonly grown in colder regions and locations.

Gewürztraminer:
An aromatic white wine grape variety that performs best in cooler climates. The variety has high natural sugar and the wines are usually off-dry, with a flamboyant bouquet of lychees. Dry Gewürztraminers may also have aromas of roses, passion fruit and floral notes. It is not uncommon to notice some spritz (fine bubbles on the inside of the glass).

Its aromatic flavours make Gewürztraminer one of the few wines that is suitable for drinking with Asian cuisine. It goes well with Munster cheese, and fleshy, fatty (oily) wild game. Smoked salmon is a particularly good match.

German wines, white or otherwise, come in a variety of growing styles:

Kabinett wines are made from grapes picked several days after the QbA grapes are picked. These are the first picked grapes of the Prädikat level.

Spätlese wines (“late harvest”) are made from grapes harvested 12-14 days after the Kabinett grapes are picked.

Auslese wines (“select harvest”) are made from grapes that have been hand-selected out from the other grapes. These grapes are late-harvest and have a high sugar content.

Beerenauslese wines (“berry selection”) are made from grapes that have been left on the vine longer than the Auslese grapes. These grapes develop the fungus Botrytis, which removes the moisture from the grape. Thus these wines are very sweet and make good dessert wines.

Eiswein (ice wine) wine is made grapes that freeze naturally on the vine and reach a sweetness of Beerenauslese level. The grapes are harvested and pressed in the frozen state. The ice keeps part of the water isolated to achieve the high sugar content of these wines.

Trockenbeerenauslese wines (“dry berries selection”) are extremely sweet, concentrated and usually quite expensive wines. The grapes used for Trockenbeerenauslese have reached an even more raisin-like state than those used for Beerenauslese.

Oh you lucky person. Look for some of these styles. Eiswein, Trockenbeerenauslese, Beerenauslese. You aren’t going to get out of the store cheaply but for a gift, you can’t go wrong.
These are quite sweet but with the balance of acid and fruit, they are fantastic.
There are too many brands or growers to be that specific since there are so many. Ask what the shop owner recommends.
If she doesn’t like wines as sweet, you could consider an Auslese.

A Riesling…Either Kabinett (kinda dry) or Spätlese (sweet)

I prefer the sweet

Riesling is good and it has a nice, sweet taste if she likes her wine sweet and not too dry

Gewutztraminer and Riesling are usually good easy drinking wines.