My grand aunt passed away recently leaving a will in which she has given equal shares of her property to all her grand nieces and nephews. She had no child of her own. I have a 5 year old adopted daughter; will she also get her legacy like her siblings and cousins?

If she named the nieces and nephews it is not likely that your adopted child will inherit.  If she just said in the will “nieces and nephews” it is possible it would include your adopted child. More research would be needed to fully address this question.