Paula Radcliffe's baby, and did she try to come back too fast?

Great story -- thanks for the link. But your question is rhetorical, I hope :)
Of course she was ill-advised: she is injured!

I hadn't heard about stress fractures of the sacrum before, but there's some suggestion that they are more common in runners than we think. They are usually misdiagnosed as low back and buttock pain due to disc problems; I guess the fracture clears up with rest and rehab anyway.

You would have thought, given as the article says "Marathons have made Paula one of the richest athletes in the UK. Already a multi-millionaire, with a luxurious new home in Monaco, she has a team of experts and advisers to help out with both her medical and child-care needs"... she would have someone keeping her from doing too much too soon. But then, trying to stop her training is probably next to impossible.

The problem she's got is that while she's breastfeeding she's losing calcium and putting herself at risk of osteoporosis. Conventional thinking now is that breastfeeding does NOT lead to bone problems, because although it alters the mother's calcium metabolism, it bounces back when the baby is weaned. Of course, they don't take into account that the mother is trying to get back to 160 miles a week ASAP!