katiestar
I see your sadfaced anecdotal evidence of badly behaved children always having done long hours at nursery and will simply quash it with the happier facts in my case.
My ds1 is the only child in his class with a working mum who used a nursery from 9.30 to 5pm each day so for argument's sake lets call it full-time. When he was a baby I worked part-time increasing back to full time by the time he was 6 months. He never experienced a seperation anxiety period at nursery unlike the children starting when they were 6 months+.
His reception teacher called him "an angel", telling me he had the best attitude to paying attention, working nicely and getting along with others despite not knowing any other children in his class when he started school. This has not changed in his 3 years of schooling so far.
BUT ALL CHILDREN ARE DIFFERENT.
IMHO, what a parent needs to do is determine which childcare best suits their child and monitor/update that decision throughtout the child's development. I am currently investigating alternative childcare for ds2 as I believe he would benefit from something different in his final period of pre-school. This is mainly because the pre-school he currently attends has taken a very staff friendly approach to adopting the EYFS curriculum and children now seem to maraud around in packs for chunks of the day rather than being gently directed in their activities. He is not being encouraged to sit and scribble and they no longer do any of the very basic level jolly phonics which they did with ds1. They tell me all the changes over the past 2 years are to do with the EYFS but it does seem more convenient for the staff too. The children only do what they want to do, outside of a couple of brief registration and circle time sessions each day. (This does not mirror the home environment where ds2 would have to fit in with my daily round of housework and errands if I were a sahm and he were at home with me).
You talk of giving up a career as "a bit of a sacrifice" . You are way off the mark there. It's huge! The off ramps are plentiful and easy to take, there are very few on ramps to get back to where you need to be plus it's way more likely that you'll be able to get some flexibility in a job/career where you are established and valued than it is that you'll find a well paid flexible job to take up once you've finished you child rearing career break.
You say a CM would provide a home environment. This too is fraught with pitfalls. A friend found out that her CM fed her dd supernoodles and peas, no meat or other protein source and the cheapest value brand yoghurt, at least twice a week. She only discovered this sort of information once her dd was old enough to reliably report on what actually was offered at lunchtime as opposed to the sample menu she was shown. Another instance I know of the CM was driving an unroadworthy vehicle daily with mindees in it and the first thing parents knew was when the prosecution notice appeared in the local paper.
Childcare is fraught with pitfalls, being a working parent is a constant juggling act, particularly if you as "muuuummeee" are the one that's really needed when illness strikes.
Katiestar, you also uphold the mumsnet paradox that no one on here leaves their career/job because they loathed it, were looking for a way out of the workplace anyway and had no desire to return after maternity leave ended. Oh No! they do it as a sacrifice because they believe they should be at home with their children, not because they simply prefer that way of life to their previous working life.
I could tell people that the worst behaved children I come across are generally from families where there is some sort of grief going on at home, violent parents, parents at war with each other, PND afflicted single mums, drug addicted/alcohol dependent parents, parents who think the type of buggy they push is more important than talking to their child, singing to them etc etc. See, lots of really awful vile stereotypes to trot out aren't there. Have you got any more you'd like to flog us working mums with ?
OP - Your quest for justification fails on many counts e.g. you don't seem to consider milestones important for the father, you're not saying he is selfish for missing them.
8am to 6pm is longer than a school day - your sister's baby will sleep through a good deal of it. Last time I checked there were no beds at school for naps and sleeping to take place. There'll be trips out in buggies etc, no walking to exert the baby.
I could go on but this is a very disappointing thread, MN ain't what it used to be as far as enlightened womanhood is concerned and support for each other's life choices.