I'm a gigantic pussy, so I usually frame this in the context of asking them something like:

"I've noticed on a few projects recently that after I've completed tasks, that you ask me about them after they've been completed and delivered. Is there something I could do better to ensure I've reported out on which items I've completed?

By holding onto it as if it's MY problem, I learn from them the best way to communicate it to the boss in the future. Then, next time it happens, I can say "wow. This is what I asked about last week in our one on one. What could I have done better in this instance. I completed this task on Monday and sent you the report before the Tuesday morning meeting. Did you receive that report? Perhaps I could list the completed items differently"

I like to blame the other party last. It could be the delivery mechanism (email, system, paper copy, etc), it could be the reporting mechanism itself (report structure, email format, etc).

If it ends up just being her... well.... at least you both ruled the other things out together and you don't come across as an ass.... but as some one trying to build a seamless working relationship.

but I'm basically a pussy.