very difficult question...as you are asking "buy a phone for a girl" Humm...
let me try (though I have failed myself in this ,....may be it work for you)
first thing first
all android value for money mobiles in India are under/around 10k like LG p500 series...dell xcd35/zte blade, Samsung b 5710, etc..
and there is a catagory of 15k+ like samsung s series or htc's, dell's,motorola etc...
between 11 and 15k all the android phones are waste of money...
so if you are thinking in terms of android then consider only these(LG p500,dellxcd35/zte blade,Samsung b7510 touch+type qwerty), and on one nice day when you have loads of time to spare then let her test (read to check the colors of these phones) in a nearby mall.
...and if she is not convinced then buy her a pink blackberry (yes some blackberry's do come in pink flavour,ask the dealer)..or whatever she says...or else you will be cursed even if her dogs doesn't like the ringtone.
and don't ever dare to challange a girl for her choice of mobile or for anything that matter, believe me you will fail miserably
....and do let us know the results...I guess ,every one wants to learn...