No you are not wrong to want the easy life, you don't have to go for promotion just because it is available. I have done just that twice, I'm a nurse and being anything other than ward based and hands on just doesn't appeal to me, so despite being offered 2 promotions to team leader (sister) in two different jobs I have turned both of them down (one before children were even thought of) because its just not how I want my life to be.
I work part time now. I could fit in more hours, but I don't want to. I don't want to be rich or powerful I just want me and my family to be happy. I think that what you need to ask yourself is whether the promotion would make you happy and if you don't think it will then leave it a while. Money is not everything, but then I'm a nurse I would say that!
Thanks for your replies, success isn't just measured in how high up the career ladder you get is it, it's about everything else in your life that's important.
I will give it some more thought, I have a while until a final decision needs to be made. I feel I have the work/family life balance about right and I don't want to tip it over the edge so I think I will probably stay put for the time being, I can always go for it again.