OP, I assume you mean in the long term. I think the only way is for one or both of you to study or train in an area that pays better. My partner started uni at 26, and it's now our 7th year of him being on low income (4 years ft uni, 2 years into an internship) (and no income for 18 months of his degree). it's been tough, but when he's fully qualified, his income will jump up a bit and there will be lots more opportunities for work, allowing us to get ahead.
It's a long road to a better income sometimes, but I figure you may as well start as that time will go anyway.
Also, remember that having babies and young kids is probably the poorest time in a lot of people's lives as their capacity to work is diminished unless they use ft daycare.
Good luck with your partner getting work. it sounds like times are tough with employment right now. what does he do for a living?