You know Shadow Tracker, she might be doing you a favor. First, she is trying to eat the destructive bees or their larvae, second, she is showing you they are there. If you watch her, she will probably be moving around tap-tapping and listening. I believe they can hear the difference in a hollow channel in wood, and will then attack that area. That is what that damage looks like to me. The bees already bored tunnels in that brace, and she is following them out for food.
I say this after having an issue with a hairy woodpecker that was damaging house siding. After a little observation I figured out that he was thinking the gaps in the plywood-type siding were bug tunnels. He would only target the places where the inside layers didn't flush up to each other and left little gaps for long lines. He would cling to the siding, sidling along tapping and listening, and when he was on one of those lines, that was where he would excavate. I started squirting calk into all the gaps I could find, and patched the ones he had already pecked out, and he finally stopped.
Good luck.