Hi Tina, and welcome to the forum.

Based on my own experience, accountancy is a pretty reasonable field to assure your employability just about anywhere in the world. I'm not familiar with the ACCA, though a quick google shows that it is an internationally recognized organization. Finding a job in the UK will depend on how well you market yourself, and how you can present your experience to be an advantage.

I'm in France these days, so can't really help much with the question of start-up costs or child care, but as a fellow accountant, I can tell you that you should be able to find a reasonable job.
Cheers,
Bev