Could you go into business with your partner? Retail has such a tradition of family owned and run businesses that it almost seems 'normal' to work together. But not every couple can handle the stress of day-to-day contact in a small shop without it taking a toll on a relationship. [I, for one, would not be able to do it...]
Try to look realistically at your relationship, your communication style, and your individual strengths and weaknesses before deciding if you would make good business partners.
One solution to working together is to have separate areas of responsibility and to trust one another to make most decisions within those areas on their own. It may help to divide almost everything into his and hers - even the office files. Do ensure though that you collaborate on all major decisions - even if you don't agree. Try to work out your disagreements in private, however, and present a united front to your staff and customers.
There is a temptation to take your work home when you work with your partner, which means you may not get a break from the worries of the business. You might like to set a time limit on work chat - no more work after 8pm or whatever timing works for you.
It may also be helpful to take one day a week off alone, plus Sunday and Monday as your "weekend together". This means that one of you is at the store all but those two days, yet you each work only four days a week - a very humane schedule, especially for families with children at home.
One of the advantages of working with your partner is the time you get to spend with each other, working toward a common goal. There are long hours to be put in when a shop is young, but you tend not to mind as much when you're doing it together [or so I've been told...].
Make sure that both of you are fully aware of your cash flow situation. Don't just leave it to one...
I'd be very interested to know how others successfully work together in their retail shops.