Is it permissible to spend the orphans' pension on an 'Umrah for their mother? And is a person held accountable for their thoughts?

The mother is not permitted to dispose of the property of her minor children unless she is appointed as a guardian or designated by the ruler, because guardianship belongs to the father or his appointed guardian, or the grandfather, and then to whomever the ruler designates. It is not permissible for a guardian or executor to spend from the wealth of minors for their grandmother's 'Umrah or Hajj, because the duty is to preserve the wealth and spend it on the minor himself in a way that serves his best interest. The grandmother is not like the father, who is permitted to take from his child's wealth. If the guardian does so, he is liable to compensate. As for inner thoughts (waswas), a servant is not held accountable for them unless he acts upon them or speaks them; they are forgiven.