Did Muhammad promise women in heaven for martyrs?
The relevant verses in the Holy Quran are as follows:
Thus will it be. And We shall consort them with fair maidens, having wide, beautiful eyes. 
‘Reclining on couches arranged in rows.’ And We shall consort them with fair maidens having wide, beautiful eyes. 
These verses make no mention of Jihad, holy war, or any type of fighting as the precondition to attain paradise.
Next, both Prophet Muhammad and the Qur’an reject the concept of heavenly reward via, “sex with beautiful women for eternity.” Prophet Muhammad clarified that such an interpretation could not be an applicable interpretation of the aforementioned verses. He said:
Allah the Exalted and Glorious, said: ‘I have prepared for My pious servants which no eye has ever seen, and no ear has ever heard, and no human heart has ever perceived but it is testified by the Book of Allah.’ He then recited: ‘No soul knows what comfort has been concealed from them, as a reward for what they did’ (32:18).’ 
Therefore, to limit Divine reward to something as hedonistic as “eternal sex” is not only contrary to Islam, but an insult to God’s bounty for those who earn paradise. The rewards of paradise are far beyond what any human can conceive or perceive in this life.
In Arabic, like in many Semitic languages, nouns are either masculine or feminine. Appropriately enough, a masculine noun is used when referring to a male and when referring to a female, an additional ‘ta marbuta’ is added to the end of the masculine noun to make it feminine.  For example, the Qur’an states:
And thou, O soul at peace! Return to thy Lord well pleased with Him and He well pleased with thee. So enter thou among My chosen servants, And enter thou My Garden. 
These four short Qur’anic verses describe the soul in Paradise both to refer to females, 89:28-29, and also to refer to males, 89:30-31. According to Islamic theology, unlike the human being, the soul is neither male nor female. This background builds the platform to properly understand the verses.
The Arabic noun translated to “fair maidens” is derived from the three Arabic letters, ha, vau, and ra, or hur [hoor]. The Arabic word hur is applicable to both men and women. It is applicable to men in its plural form, ahwar, and applicable to women in the same context. This title, bestowed upon an individual, indicates a character of having beautiful eyes—a reward for those righteous souls. It also indicates an intense whiteness to the eye. Both of the descriptions refer to spiritual matters, having nothing to do with any sort of hedonistic physical gratification.
Moreover, hur has no gender, but Islam teaches that no soul can reach its full potential until it has a spouse. Thus, this verse demonstrates that one reward of paradise is that the soul of each person—whether male or female—will be given a companion with which to celebrate paradise.
To be sure, these are yet metaphorical explanations that will more effectively be understood in the afterlife. In the meantime, suffice it to say that the allegation that the reward of martyrdom is hedonistic pleasure is a belief that finds no support in Islam in any capacity. This is clear from a sincere study of the Qur’anic Arabic.
 Geert Wilders, Marked for Death: Islam’s War Against the West and Me 42 (2012).
 Id. at 125.
 Qur’an 44:55.
 Qur’an 52:21.
 Muslim, Book 40, #6780-83.
 Arabic Dictionary available at http://www.languageguide.org/arabic/grammar/.
 Qur’an 89:28-31.