I have somehow managed to enjoy a bit of 'maternity leave' even though I'm a single mum and had no savings. I stayed part time at my employed job for the sole purpose of receiving maternity pay but, even so, it's basic SMP (c.£640 pcm). This plus a bit of tax credits is enough to cover my (thankfully very low) mortgage repayments, basic bills and food.
Aside from the big project when DD was 8 weeks old, I didn't do any work apart from bits of admin until DD was 4 months old when I resumed working 6 hours a week. I paid a babysitter to come to the house while I worked. I had to do this to retain my clients. It has been very very hard at times, listening to DD crying at the babysitter.
I feel guilt that in DD's first few months I wasn't there for her 100% plus guilt for not being able to give my work 100%.
Like others have said, I wish I could have just completely focused on being a mum for the first 9 months without this nagging feeling that I 'should' be getting work done whenever there's a chance.
Having said all that, this will be worth it in the long run. If I went back to my PAYE job DD would be in childcare for 12 hours a day (2 hour commute to London office) at the end of my maternity leave. So, on balance, maybe me having to give a bit of myself to my business in the early months is offset by the benefit to DD of not going into long days of childcare from 9 months? When she goes to school I'll be able to take her and pick her up, I'll be able to put my work down and go to her school assembly or whatever.
It'll always be tough juggling being a good mum and meeting deadlines though, but that could be said of working for an employer too.
Not having the security of sick pay is my biggest long term concern.