Finances are a common source of strife in marriages. Getting and staying on the same page is critical. Communicate about finances openly and often. Budget together. Review the budget together regularly. It sounds like you are already starting this. That is a good sign. Never stop.

As far as your specific question: I'd recommend joint for day to day and emergency fund. While its simpler, the main reason is mental: its not my money and your money, its our money. We do keep investments separate, but its still "ours".

That is just a recommendation though. Its more important that you both talk about and agree on your approach.