1) When writing will so in this will 1/3 estate should be spent on the person herself when she dies like it should be spend on qadha fast and salat. If someone has not gone for Hajj while alive so in her will she says some of her estate should be given to someone to perform hajj on the deceased person’s behalf. My question is should the person put in her will that the money that should be spent for hajj should be from 1/3 that is for her qadha salat and fast or it should be from money that she left for her family as inheritance?

2) Can someone say in her will that everything and all her money etc should be spend on her qadha fast and salat without leaving anything or money for her relatives because she has a lot missed salat and fast or no?

1) Yes, you should specify in your will that the 1/3 of the estate should be spent on obligatory hajj, lapsed khums, etc.

2) No it is not permissible to do that. In general, a person has disposition over 1/3 of their estate and there are specific rules to adhere to. The same rule applies irrespective of how much money a person leaves behind. She still only has a right on 1/3 of the estate. However, she can ask her inheritors to fulfill those lapsed obligations for her