In most jurisdictions the niece and nephew would need written evidence to convince the court that their uncle intended for them to inherit his property. A promise to devise real estate must be in writing. If he failed to execute a will then his property will pass to his heirs at law according to state intestacy laws. If he had no children and his parents are deceased then his share may pass to you as his next of kin. (Ask the question "Who inherits in an intestate estate?" for a link to state intestacy laws.)
You can inherit property by virtue of a will: testate. You can inherit property under the laws of intestacy if there is no will: intestate.
You can inherit property from your mother-in-law if she mentions you in her will by leaving a gift. If she dies intestate, or without a will, you are not her legal heir.
If that person had legally adopted the daughter then she would be his legal heir. Otherwise the only way she could inherit his property would be by his will and she would not be considered as next of kin if he died intestate.
Your question seems to imply there is another person on the deed with your brother. What happens to the property upon his death depends on how the property is held. If the deed granted the property as joint tenants with the right of survivorship the title automatically passes to the surviving joint tenant. If the property was acquired as tenants in common and the brother died intestate then his interest would pass to his next of kin and his wife would likely inherit his half interest in the property. You may need to seek the advice of an attorney who specializes in probate in your area. You can check the laws of intestacy at the related question link below.
An estranged husband is married and he has all the rights of a surviving spouse if his wife dies. He will inherit an intestate estate according to the laws in the jurisdiction. He will become the sole owner of any property owned by survivorship with his wife if she dies.
One would surmise that whomever real estate is left to in a will would inherit it. If someone dies without a will, then the Texas Intestate Succession laws will determine who inherits the property.
Your stepmother's next of kin would inherit any property she owned at the time of her death if she died intestate, or, without a will. You can check your state intestacy laws at the link below.
The orphan would need to be able to prove a blood relationship with the decedent.
That depends on where your father lived with his last wife, how they held title to property, if he died testate or intestate and the laws of intestacy of the state where he died or owned property. If your father owned his property as a joint tenant with the right of survivorship with his third wife then you get nothing. If he acquired his property during his marriage in a community property state then you get nothing. You may inherit a portion if he owned property in his own name and died intestate or if he left property to you in his will. It depends on a lot of other details.
if my father's brother wants to share in our property what did my father do if he didn't want to give him any share becoz hedidn't spent any money on this property
a woman or girl who will inherit property is called a heiress
In Virginia a couple cannot acquire marital rights by living together. If the couple is not married then her children would be her next of kin and would inherit her property if she died intestate. To determine who would inherit your mother's property you can check the laws of intestacy for Virginia at the related question below.