Will For Thai Girlfriend

I would like some advice on drafting a will for my Thai girlfriend. She is the owner of 1 Rai of Land which i have a thirty year lease on and i have recently build a house in my name on the land and would like to protect the land from going into the wrong hands (Issan Family) should anything happen to her basically i would like her to leave the land to my one year old daughter in her will and to name me as my daughter guardian until she is 18 is this possible also do i need to register the Will i read somewhere that it could be done at the land office ?