I can understand her refusal if he was asking for help in military conquest, but this seems to be a war of defence.
Can’t she at least act as a deterrence against war? She can’t keep her promise to the first king if can’t at least use her powers to protect the country.
That's why she called it a baseless conspiracy. It's not just about money, but politics. People are after her not just for her vast wealth she may or may not have claim over, but also a secret conflict that could be made public to create a social upheaval or political victory.