The original argument she is responding to was that the wedding of Kate Middleton and Prince William was paid for at public expense and so the public is owed an heir or two. But that seems wrong for the reasons Kazez gives:
Charles Foster says, "Most people have no obligation to reproduce." Wills and Kate, though, are a special case. Millions of pounds were spent on the wedding, and now they owe the British people a couple of little heirs to the throne.(By the way, Bollinger is a kind of champagne, bobbies are police, and Fortnum and Mason is a fancy food store in London.) "Babies are not for sale" seems to hit the nail on the head to me. But what about the idea that the royal couple owe something in return for all that expenditure? I think in having a monarchy, and a monarchy of a fairytale type at that, the British are accepting a kind of trade. The royals get things like this wedding and palaces to live in, etc., while the people get this kind of spectacle, a speech on Christmas Day, and so on, plus whatever profits there are to be made from the tourism thus generated. Those who don't like the deal can try to end it in the usual way, by voting for politicians who offer to end it.
The money has been spent primarily to ensure dynastic continuity. By accepting our money for their Bollinger and bobbies, William and Kate are impliedly accepting our commission to use their best endeavours to breed. They have taken the People’s Shilling, and have become, first and foremost, breeding animals. Their gametes are held in trust for the nation, and they should guard them. Kate must marinate her eggs in the finest organic nutrients that Fortnums has to offer: William must never wear tight underpants, and always wear a box when he plays cricket.Forgive me if I don't understand the phrase "Bollinger and bobbies" and don't know what Fortnums are, but I really would have thought the People payed for a wedding and got a very fine wedding. They can hope for little heirs, but it's understood that babies are not for sale. So William and Kate do not owe the British people anything.
It has been odd to see so much excitement about the wedding among my American friends and so much aversion to it from my British friends. But then the Americans aren't paying for it and don't have to live with the deal the British, for now and as a whole, seem to accept. Those who object seem to dislike not so much the expense as the symbolism of the whole thing, the idea, roughly speaking, that rich and powerful people are better than everyone else and deserve to be loved even by strangers. It is the myth of aristocracy (i.e. the myth that we are ruled by the best people). Those who enjoy it enjoy it as a kind of myth or fairy story. In short, no one thinks it is true, but some people enjoy the fantasy while others see it as dangerous or evil (because false).
So it's a bit like some of the debates over religion, with anti-monarchists playing the role of the atheists. It also seems like an issue where fictionalism might be worth taking seriously. If Britain keeps its monarchy for the sake of the tourist industry or out of Burkean caution then it might be a good idea to enjoy it rather than rage against it. And the enjoyment is likely to be greater if we engage in a bit of make believe. This is not my view, but it's one I could imagine a reasonable person taking.