Those were donations from private citizens.
As a government, the U.S. supported the U.K. - not specifically against the IRA, but as a general policy.
Agree with the first part - although there have always been rumours that the CIA or other parts of the USA government did help fund/supply or otherwise assist some terrorist groups in the UK I treat those claims with a lot of skepticism.
However the second part is only partly true for instance the USA government never outlawed NORAD and I don't think it is controversial to say NORAD funds did go toward killing UK citizens. There were also other areas where the USA did not exactly go out of its way to assist the UK. I believe there were instances when extraditing either suspected or even convicted terrorists proved very difficult, also very little co-operation in helping UK authorities trace finances of suspected or convicted terrorists and so on.