They need to know that she will be coming back to Thailand ie kids a home and a job and have some money for the holiday, plus your information will help her
you will need a legal will and make sure that you have two witnesses to sign the will, it takes approximately one year to get the money transferred as you will have to go to court to claim the money from the bank account, the bank will not give you the money until the courts have done the paperwork for you, your best bet is to take the lawyer with you when you get the paperwork for the money, you will need the death certificate it's not easy you will need help from the lawyer or a good friend that is thai