Praise be to Allah.
There is a grave error that is committed by many of those who want to get married and who are looking for life partners, both men and women, which often leads their plans to failure, because both parties fall victim to stress and grief, and society bears a new burden as the result of divorce and its consequences.
The reason for this mistake is fanstasy, whereby one of the couple wishes that his or her partner would change in the future to become their dream partner which they always imagined when they were younger, and that every shortcoming is going to be replaced with perfection.
These people try to ignore the present and look to an unknown future, shunning reality and hoping to avoid confronting it. They forget that what is required of everyone who gets married – if they want it to succeed – is to be realistic in their conditions and choices, and realistic in accepting or rejecting; they should not base it on illusions or fantasies. Rather they should see the present as it is and base their decisions on that foundation, so that they may bear direct responsibility after that.
The reality of this girl indicates that she is not religiously committed, and she is not suited to you. Your Prophet (peace and blessings of Allaah be upon him) advised you to marry the one who is religiously committed, and this is what you should do. Your claim that her family have accepted you will not benefit you, because you are going to live with the girl, not her family, and all they can do for you is to ask you to be patient with her, regardless of how she treats you.
It was narrated from Abu Hurayrah (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “Women may be married for four things: their wealth, their lineage, their beauty and their religious commitment. Choose the one who is religiously-committed, may your hands be rubbed with dust (i.e., may you prosper).” Narrated by al-Bukhaari, 5090; Muslim, 1466.
Al-Haafiz Ibn Hajar (may Allaah have mercy on him) said: What this means is that a man who is religiously committed and of noble character should make religion his focus in all things, especially with regard to long-term matters. So the Prophet (peace and blessings of Allaah be upon him) enjoined finding a wife who is religiously committed, which is the ultimate goal.
Fath al-Baari (9/135)
Al-San’aani (may Allaah have mercy on him) said:
This hadeeth indicates that keeping company with religiously-committed people in all things should be the priority, because by keeping company with them one may benefit from their good attitude, blessing and ways, especially one's wife, because she is the first one whose religious commitment should be considered, because she is to be his close companion, the mother of his children, the one with whom he trusts his house and his wealth and herself.
Subul al-Salaam (1/146).
We advise you to seek the help of your Creator, may He be exalted, to get married. Do not think that marrying this girl will never cost you a great deal, because it seems that she would make many demands even if that leads to your being poor. Do not worry if you forget about marrying her and marry someone else, because Allaah has promised to help the one who wants to get married in order to preserve his chastity.
It was narrated that Abu Hurayrah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “There are three who are all entitled to Allaah’s help: the one who fights for the sake of Allaah; the mukaatab who wants to pay (the price of his freedom); and the one who gets married seeking chastity.” Narrated by al-Tirmidhi (1655), al-Nasaa’i (3218) and Ibn Majaah (2518); classed as hasan by al-Albaani in Saheeh al-Tirmidhi.
Al-Mubaarakfoori (may Allaah have mercy on him) said:
“the one who gets married seeking chastity” means chastity from zina. Al-Teebi said: The reason why he said that was because these are difficult matters that may weigh heavily upon a person and break his back, and unless Allaah helps him he will not be able to do them. The most difficult of them is remaining chaste, because that means suppressing the desire that is created in him and because it is an animalistic desire that may pull be down to the lowest level, but if he remains chaste by the help of Allaah, he will attain the status of the angels and the highest part of ‘Illiyeen.
Tuhfat al-Ahwadhi (5/242).
To sum up:
As this girl is now, she is not suitable for you to marry her. If she resolves to change for the better and tries hard to achieve that, then marry her, but if she insists on carrying on as she is, and is not sincere about changing, then leave her and look for someone else. We ask Allaah to help you to do that which He loves and which pleases Him.
And Allaah knows best.