This is actually something I really object to about the direction modern feminism has gone in. They don't seem to get that there's a difference between supporting someone's stupid or reckless decision and supporting their right to make that stupid or reckless decision in the first place. I believe that denying someone's right to have a child they want is wrong, in the exact same way that it's wrong to deny someone's right to a childfree life. But I also believe that if you're going to stake a claim to certain rights, you mustn't take the piss.
The Suffragettes and other early feminists demanded many basic rights that we now enjoy - the right to vote, the right to education, the right to work, the right to equal pay and working conditions (although I know we're still some ways off on some of the work issues). They demanded these things, not just because we plainly deserved them as human beings, but also because they knew that women were just as capable of handling such things as political decisions and fulfilling workplace expectations as men were. As such, I find it quite galling whenever I hear of women throwing away these rights - it's their decision to make, of course, but that doesn't mean I can't be annoyed about it.
Things get messy when other people start getting dragged into it. Mothers making unreasonable demands about maternity leave or flextime irritates me because it potentially casts all other women of childbearing age in a negative light. I'm lucky where I work, but I know that smaller companies have - and are - refusing to hire women of childbearing age because they can't afford all the expenses associated with maternity leave. Even those of us who don't plan to have any, ever.
And when you're actually responsible for a whole other life, one which is wholly dependant on you for a significant portion of its existence, you really don't get to take the piss with those responsibilities. No, it is not anti-feminist to suggest that a woman should hold off on having kids if she can't afford to have them right then, it's just good sense. I know some feminists object to this thinking on the grounds that it reduces children to the status of mere commodities, but I think that's missing the point - a child is a person, they need to eat, they need to be clothed, they need adequate shelter, they need education, and furthermore they have a right to all these things. And while I don't advocate taking anyone's rights away from them, I do believe that some rights trump others. A woman saying "yeah, I can't afford to feed them, and school fees are way too expensive, and we're behind on the rent... but I still have a right to have them!" is selfishness, pure and simple, because in exercising her right in that regard, she's diminishing (or denying outright) her kids' most basic of human rights.
And that's not even going into the strain that's placed on the economy as a whole by people claiming benefits. Once again, of course people should be able to claim benefits to help support their kids - raising children is more expensive than most people can handle on their own, of course, and people can find themselves in unexpectedly dire financial straits and it's just heartless to say "it's your own fault for having kids" or whatever. But women (and men - I've seen families where neither parent works because they know they're earning more on child benefit) who just keep having kids and saying "oh, I can get by on child benefit, I don't need to work" are, through one means or another, making life more difficult for everyone else, and that's not really fair. And so I reserve the right to object to people who make decisions such as these.