Sister, I would strongly advise you to consult someone of Knowledge (scholar, Sheikh etc) and tell
them about your situation. Because there are a number of complicated and serious factors involved here such as the issue of cutting of blood ties and obeying or disobeying your parents.
As regards to severing ties of kinship,
"There is no sin more deserving of having punishment meted out by Allah to its perpetrator in advance in this world along with what He stores up for him in the next world than oppression and severing ties of family." [Tirmidhi]
n also "Whoever believes in Allah and the Last Day, let him maintain the bonds of kinship." [Sahih Al-Bukhari]
Allah has cursed the one severing family ties (qata ur rahm):
"And those who break the covenant of Allah, after its ratification, and sever that which Allah has commanded to be joined (i.e. they sever the bond of kinship and are not good to their relatives) and work mischief in the land, on them is the curse, and for them is the unhappy home." - [Ar-Rad 13:25. See also Muhammad, 47:22-23].
A cursed person is one who is deprived of the mercy of Allah. It is an indication of this deprivation that this sin is punished in this world as well as in the Hereafter.
Breaking of the ties of kinship is
forbidden for personal reasons, but in some cases, not only is it permitted, but it is a must. When we do it solely for the sake of Allaah, to establish the Deen. One of the most vital concepts in Islam is Loving for the Sake of Allaah, and Hating for the sake of Allaah without which our eemaan is not complete.
The Prophet :arabic5: said: "He who loves and hates for Allaah; and gives for Allaah and withholds for Allaah- has perfect Eemaan"
[Abu Dawood]
In
some cases we have to withdraw from our family members for Allaahs sake, because they are disobeying Allaah.
But, to know where/when to withdraw or boycott from family and to know where/when to not withdraw or boycott... this is for someone of Islamic knowledge who knows and understands your situation to see what applies in this case. Have your parents fallen out for a personal reason, or only for the sake of Allaah?
According to Imam Ibn Tayymiyyah, in his book
"Commanding the good and Forbidding the evil", he says that if a member of family is disobeying Allaah, do not boycott from him/her as that is not wise, but explain to them and bring them towards Islam gently. Because if u boycott them, there is strong possibility they will go worse. But then again, sometimes not boycotting or saying anything makes one go worse. So we have to be wise and see which approach would give the best results with regards to our duty towards Allaah and our family.
As for the case of disobeying the Parents, Allaah says in the Qur'aan:
"We advise man to be good to his parents, but if they try to make you do in My name what you know to false, do not obey them"
[29:8]
But m not sure whether what your parents are doing is wrong or right or wise, because I don't know the reason why they are not speaking to her. Again, I strongly advise you to refer your case to a scholar, tell them the complete situation, and inshaAllaah, they will tell you the most wise and correct approach to take in this matter.
If u don't know any scholars u can ask, then let me know your case, n I'll try and put it through to someone I know who can guide you inshaAllaah.
May Allaah help you and your family. Aameen
EDIT: saw this now,
What your parents are telling you to do is Haram. We even have to keep ties with our non muslim relatives. Why should we cut off our muslim relatives if they sin?
Because in
some cases n situations you have to fall out with relatives for the sake of Allaah. (e.g. when they are disobeying Allaah's commands and commiting major sins even after knowing they shouldn't. Then it doesn't matter if they are your son or daughter or father. If they are breaking Allaah's commands and not listening or taking heed even after you have explained to them and been gentle, then u fall out with them until they realise and repent. Our love towards Allah comes first, before our love to our sons, daughters, spouses etc. We have to take a stand sometimes. How else would Islam be established within our homes and elsewhere?
But our approach should be wise. Before commanding the Good and Forbidding the evil, we need to see if we are in a position to do that (e.g. parents are in a position and able to forbid their children). Then we need to know and understand the persons/childs background. We need to have some insight into which approach to use. Some people need harshness and some people need gentleness. Depends, every situation is different.