for my two penneths worth id consider the folowing:-
1:- if you go for the 45k job, your expenses will soon come up to meet any income you bring in, you cut your cloth to suit as they say, which means it will be harder to make a move from the job if you dont like it.
2:- if quality of life and family are more important then go with that
3:- job satisfaction and happiness at work is worth everything. ive done jobs i hated and it makes you miserable, at home as well as work
4:- unsociable hours can be great when your being paid for them, but when your trying to raise a family and you want to be at home then theyre like a prison sentance.
only you know in your heart what you really want to do and whats important. As an ancient greek said, say no and you regret it for the rest of your life wondering what could have been, say yes and you will know and be happier. trouble is which to say yes to!
good luck with whichever one you choose, but remember its yur life