All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.

Dear sister in Islam, we would like to thank you for the great confidence you place in us, and we implore Allah Almighty to help us serve His cause and render our work for His sake.

Jurists have differed with regard to whether wearing niqab is obligatory or not in Islam. Anyway, the woman who wears niqab has no right to censure the woman who wears only hijab, describing her as falling short of her religious duties. Nor should the woman who wears hijab criticize one who wears niqab for being inflexible and extreme. Both should coexist in an atmosphere of harmony and mutual love, and both, Allah willing, are also right with respect to their attire. Islamic attire, be it  niqab or hijab, shows that the wearer has adopted Islam as a way of life that is reflected in her morals and dealings.  

In his response to your question, the eminent Muslim scholar Dr. `Abdul-Fattah `Ashoor, professor of exegesis of the Qur'an at Al-Azhar Univiversity, states the following:

Reviewing the history of Islamic Law and what has been revealed in the Qur'an and the Sunnah on the subject at hand, one finds the following:

1. Sufur (woman's unveiling her head and part of her chest) was usual in the pre-Islamic era and remained as so until Almighty Allah revealed the following verse in AH 5: (O Prophet! Tell thy wives and thy daughters and the women of the believers to draw their cloaks close round them (when they go abroad). That will be better, that so they may be recognized and not annoyed. Allah is ever Forgiving, Merciful) (Al-Ahzab 33:59). "Drawing the cloaks" round Muslim women, according to this verse, refers to covering their faces and bodies so that only their eyes are left unveiled. Commenting on this verse, Ibn `Abbas (may Allah be pleased with him) said, "Almighty Allah has ordained the believers' women, when they are to go abroad for some purpose, to cover their faces from above their heads and to show only one of their eyes."

Then, after the battle of Banu Al-Mustaliq, in AH 6, Almighty Allah sent down the following verse: [And say to the believing women that they should lower their gaze and guard their modesty; that they should not display their zeenah (charms, or beauty and ornaments) except what (must ordinarily) appear thereof] (An-Nur 24:31). Ibn `Abbas (may Allah be pleased with him) said, commenting on this verse, "'What (must ordinarily) appear thereof' here refers to the (woman's) face, hands and rings."

2. Ibn `Abbas, the knowledgeable scholar of the Muslim nation, would not contradict himself (as might be indicated from the seemingly contradicting comments on the verses quoted above). What he said as comment on the first verse referred to above explains what its words indicate, and what he said commenting on the second verse marks gradualness in legislation (from wearing niqab to wearing hijab only). In this context, the first ruling, wearing niqab, remains optional to one who desires to wear it and whose circumstances so allow. This will be a praiseworthy step on her part. The second ruling, covering the woman's whole body except the face and hands, is the ultimate obligation that the Islamic Shari`ah ordains on every Muslim woman.

3. It does not befit Islamic behavior that a woman who wears niqab criticizes one who only wears hijab or vise versa. She who observes firmness — implying an additional act of obedience in wearing niqab — is praiseworthy and will be rewarded (by Almighty Allah) for it; whereas there is no blame on one who adheres to wearing hijab only. However, it should be taken into account that she who chooses to unveil her face and hands should not gaudily adorn herself (by putting on makeup and the like), as do some women who wear head covers.

Based on the above, the questioner may choose the way of dressing which she likes (so long as it suits the Islamic attire for women) and there is no blame on her for either choice she may make in this regard.