Being the culprit of this question (i play the dwarven girl in question) giving some thought and checking in the novels (mainly the drizzt novels, as those focus around a lot on Mithril Hall and its dwarven inhabitants). I think i can give an answer:
First and formost: Dwarves are neither small humans, nor are they all the same in the broad sense (they do have some stereotypes they share more with each other). And also in the novels if it comes to presents there seem to be no gender specific destinction, its clearly noted that they behave pretty much the same, and some are even undistinguishable from the males (like on the book of the drow invasion one non-dwarf asks why only a few females fight, and gets the answer that nearly half of them actually are woman), so good gifts for any dwarf is also a nice gift for a female one.
In general can be said:
- inviting to a mug of ale or beer is always a nice one for any dwarf,
but it propably comes, without being to flirtous and just friendly
(but at least dodges the marriage proposal completly), a special brew
from a dwarven run tavern may be a better choice then grog in an
harbor inn.
- precious gems are propably the most common desireables of dwarven
woman, but like with humans its not just general, one like some types
of gems or shapes more than others, maybe natural, maybe polished,
but some may even dont like them that much at all
- as in the other answer high quality crafts are a good choice, but
again it may vary, one fancy a fashionable mug, another a finely
crafted weapon
- also artifacts of old dwarven kingdoms, or just a book about them,
are highly recommended, dwarves seem to have a very keen sense on
their history, ancestors and forefathers
That said its also possible that dwarf desire entirely different things (they are not all the same after all), dwarves living in human cities seem to fancy some more human stuff too, Dwarves from more remote mining outposts maybe even love a nice meal over all other things.
So finding out about the dwarven girl is always a good thing to do, just as one would do with human girls.