Please help resolve an argument I’m having

So I was trying to place a limit buy order for Doge but placed a market order instead. The amount was 20k and the price was 0.22 cents/doge. Upon realizing my mistake I immediately sold it back, at a loss of about $20 (the spread).

Now, this account already had 5k worth of doge in it, which my wife had bought a few years ago at a cost basis of .19 cents. But now it shows the cost basis as .21 cents. I know there was no money lost besides the spread and this has more to do with an accounting rule (FIFO I believe).

But my wife is now complaining that the transaction I made increased the cost basis of our doge from .19 to .21 cents. She’s saying if the price of doge now drops to .19 we will lose money, and the profit that was showing there before has “disappeared”. Surely this can’t be accurate, right? How can I explain to her that just because our cost basis is now higher it doesn’t we’re at a disadvantage relative to our previous position?