[refurb]

Assuming OP is in the US, if they were to divorce, the income earned while married is generally split equally. So it's a bit odd to talk about "his money" and "her money" when married unless you're talking about assets from before the married that have been kept separate.

The best approach is to agree to a financial plan as a couple and then go from there. It might involve contributing a portion of each persons salary to a common pot. Or maybe just setting it aside individually for that purpose.