family together or career goals

Hey ladies, I really hope I don't sound like a monster in this post but I'm having a hard time deciding between a job opportunity that has come up and my family.
My partner is in the defence force and for me to be able to work we have had to move back to the town my family is in and you partner stay where his work is. We are only meant to be separated for another 12 months before we live together again.
Anyways I've been doing great at work and a opportunity has come up where I can gain a further qualification and work at the same time (which this qualification is way out of reach otherwise). The catch is this means we will all be seperated for 2 years instead of 1 and I'll be putting off having another Bub for 2 years instead of 12.
I really want this job opportunity and I know I'll be satisfied with the qualification once it's complete but I also want my family together and don't want to be kicking myself later because I turned down this opportunity.
But then should I wait and do this qualification once my child/future children are in school? Also will my child "hate me" for taking on more hours,and her being away from Dad longer ect. They are young and handles our current living arrangement really well but yeh I don't know what's best/right for them. As you can see I'm so confused.
I'd like to know your experiences if you have similar? What you did? How would you way this up?
Thanks heaps I really I don't sound to selfish.