Interesting thread. I can say it quite clearly, stopping work to focus on my family is the one and only regret I will ever have.
I left when I was at the top of my career to become a "trailing spouse". I didn't need to work as exh was earning well enough and in any case, I was working in a very specialised sector so there was absolutely nothing for me job wise in the places we landed. Even when I tried everything, sent 100s of CVs out, went into retraining and both times I graduated with honours, but there were no jobs for me in the area chosen by exh.
DS was born with a multitude of health problems that required some attention in the early years so I stopped looking for jobs for a couple of years, once I went into full search mode it was practically impossible for people to take me seriously with such CV gap. Whatever people say about equality, it doesn't matter how justified and good is for the mum to take care of the children, the lack of recent experience seriously hinders any job search.
I never recovered, I have been working for a few years in admin jobs which are lovely but dead ends, no career progression, in paper I am now no longer a manager, a lecturer, or whatever I was in the past. With luck I will get to what was my first professional salary 20 years ago in about 3 years time.
What makes the matters worse was that despite the career sacrifice on the family altar, once the marriage went down the drain, I have been left in such bad financial position that without the blessed tax credits DS and I would be living in the street. Obviously I'm not saying that your marriage will fail, but accidents happen and having a single income in the family is, now and to my view, a very irresponsible decision. Yes, I was there to suport my husband and to bake and take DS to the park... at the expense of not being able to provide for him as I should nowadays.