Ouch, that could be a reason for the fighting, you basically saying her goals aren't as important as yours, is selfish and could hurt her feelings. Perhaps you just worded it wrong when explaining the story to us, but if not just be sure you explain to her that her goals and dreams of having a family is important to you, but you first want to be financially ready for all that. Tell her you want to get your career started so you can support her and your family together, so you're working together.

Good luck.