What right in property does an adopted daughter have?

Please tell us whether the property of your aunt is ancestral or self acquired?

It is very important to know that because the whole distribution of property depends on the status of the property.

Assuming you’re aunt is a Hindu,

Basically an adopted child have equal rights in the property as compared to the natural born child.

So, if the property is ancestral then the adopted daughter will have equal rights in the said property.

But if the property is self acquired, then your aunt can dispose off the property as per her wish by making a Will.

If she makes a Will in favor of the natural born daughter then, the only option available to her would be that she can contested the said Will.