MPs have backed a new law allowing Princess Anne and Prince Edward to stand in for King Charles at official engagements.
The Counsellors of State Bill passed all its Commons stages and is now set to become law.
Princes Andrew and Harry remain on the list of stand-ins, even though both have stood down as working royals.
The Prince of Wales, Camilla, the Queen Consort, and Princess Beatrice are the other counsellors of state.
The legislation has been fast-tracked and cleared the Commons earlier on Thursday with MPs giving it a series of unopposed readings.
The King, the Queen Consort and Prince William are all expected to undertake overseas trips in the next 12 months- and without these additions, it was feared there could be a lack of available stand-ins for the monarch.
Chancellor of the Duchy of Lancaster, Oliver Dowden, told the Commons: “This is a Bill that supports the monarch, our head of state, in discharging his constitutional duties.
“This Bill guarantees the continuity which we in government and Parliament depend upon to serve the British people.”
Ms Fulani, founder of the charity Sistah Space, has expressed her shock at being asked by the late Queen’s lady-in-waiting, Lady Susan Hussey, where she “really came from”, describing what happened as a “form of abuse”.
Lady Susan, the Prince of Wales’s 83-year-old godmother, has resigned from the royal household and apologised.
Speaking in the Commons, Mr O’Hara said “certain parts of the institution seem stuck in the past”.
“And the treatment last week of Ngozi Fulani at Buckingham Palace was appalling. And I’m delighted that the Prince of Wales…”
Commons Deputy Speaker Nigel Evans cut him off and asked him to “focus on that legislation please”.
Mr O’Hara also asked why more royal duties could not be carried out digitally.
“Is there any legal impediment to the monarch appearing via a video link to join a meeting of the Privy Council? I don’t see why any of that should be controversial,” he added.
But former Attorney General Michael Ellis said: “Not everything can or should be done via online media platforms. The functions of the monarch sometimes do require physical presence. Often, they do.
“Either for important legal reasons of state or for ceremonial reasons.”