There are a group of Indians who have made it their life goal to constantly carp about the caricaturing, ridiculing, denigration and bizarre interpretations of Hinduism. This uncharitable practice of some Americans is not illegal or inconsistent with freedom of speech and the Bill of Rights. It does not incite hate crimes and allows one to persist in one's beliefs and practice them. Their behavior maybe unfair, uncharitable and uncivil, but those are not guaranteed by any statute or the constitution.
It is not uncommon for one culture to look down upon an alien one on the basis of genuine or imagined material or moral superiority and even to counteract, compensate for and rationalize its own moral or material inferiority.
Religion is a matter of faith and not reason.
If your Hindu faith is strong enough, you may ignore them as you would any barking dogs. If you feel the need for defending yourself, it is because you put some value to their low opinion of you or your religion or you wish to educate them and claim your proper and deserved seat at the common table. Lastly you can expose and publicize the foolishness, inconsistency, absurdity or idiocy of their beliefs.
There is one other thing that is more important to do than all of the above, and that is to examine your own beliefs and see whether the abuse and ridicule are deserved. One hundred fifty years after Darwin and the Theory of Evolution and with all the supporting data, it is somewhat unintelligent to believe in a god and downright idiotic to conceive a chimeric one, part monkey or elephant. One should not be surprised that someone desirous of proving their superiority or over-reacting to compensate for their inferiority, beats up on you about it.
While it is true that the Upnishadic Hinduism is monotheistic (one too many for me), the vast majority of Hindu Indians worship many gods and bow to trees and snakes. Why a few years back they had a goddess for smallpox or all poxes and beliefs in astrology, charms, amulets and 'BADHAS' are widely prevalent. Cows are still worshipped and afforded a special status with processions and proclamations to ban cow-slaughter. The Ganges is polluted along its entire course in the plains and fragments of incompletely burnt dead bodies are seen around the Varanasi ghats. There is no doubt that there is pollution in all major cities and fecal or urinary odor in trains and buildings. Civic sense is lacking and betel stains and graffiti widespread.
Such criticisms as the American schoolgirl of Indian origin experienced are not completely unjust even if they are unpleasant and bad for an immature young child.
To take umbrage at the truth is pretentious, hypocritical and downright immature. My amused response with a patronizing sardonic smile to the arrogant superiority is to use a simple anecdote to put them in their ridiculous place.
A teacher in a math class posed a question, 'What is the answer to ten minus ten'? All of the class except one student answered anywhere from two to ten. The solitary student who had answered one, then incessantly bragged that his answer was intellectually the closest to the correct one. The irritated teacher calmly explained that the falsely proud student lacked the fundamental concept of mathematical truth just as badly as the rest of the class and his miss was as good as a mile.
We are a century behind the West in many things and need to stop the blame transference game. If we were foolish, apathetic, docile or willing to be colonized, I am not surprised that we are so backward or poor. If I move into your house permanently, I have no reason to expect the same treatment that you give to your family. I cannot expect that you will afford me the same time, importance and affection you give to your family. Thus they are going to devote more time and pages to Christianity, however undeserving it may be or not.
Finally have you considered why they don't criticize Jainism, Buddhism, Zoroastrianism, Islam or even Sikhism, the way they criticize Hinduism. You should read some of the myths of Shiva and Parvati with the details of sexual activity to realize that they provide a fertile medium for such psychosexual speculations, however unjustified and offensive they may be. I also realize that they do not mete out the same treatment to Greek gods and goddesses, even though they provide even more sources of psychosexual fantasy and deviation. While it may be true that only a fool exposes the skeletons in his own closet, only a bigger one stores them in reverence enough to worship them!