I think a few of us are missing the point.
Being a single parent with/without a job isn't equivalent to being a married parent with/without a job.
It carries a whole different set of restirctions, responsibilities and pressures, which are not immediately obvious to those not availed of experience.
Often, indeed usually I believe, in a marriage, the home related work is shared; a single parent carries all of this, and yes, there might be less washing if there's only one of you, but the bins still need putting out, the property maintained, the rooms cleaned, bills paid, shopping done, cooking done, car fixed and washed...I could go on, but all the things a husband would normally do, have to be done by you as well as your things.
This is just one aspect. If you have a medical appointment you don't have the luxury of asking your husband to take an hour off to drop the children at school - it's you or no one, and often you just don't go, because you've no one to share responsibility for the children.
It's all very well to say 'Well, ask a friend' but that's not the same - some single parents don't have many friends, as they never get out, socially - another issue that arises when you are alone.
And if you ask a friend, that generally means you will have to reciprocate the favour for that friend, which is sometimes just impossible - I have couple friends who expect to swap childcare and don't have a clue how little spare energy or time or resources I have. If I can't return the favour I don't ask it.
It's just not as simple as it seems.
It's a bit like saying 'Oh, I want to buy this house, but it's got two bedrooms, can I have it half price?' It just doesn't work that way iyswim.