Helpful Coworker has decided that, as I'm 20 years younger than her, I will be grateful for her helpful bits of advice and information. Said "helpful" bits of advice and information have ranged from her informing me that I can't be afraid of dogs when I mentioned that my uncle's dog doesn't like me (I've had dogs since I was 3 years old, and love them. No fear here!) to telling me I should do x, y, or z with my side business - all things that are pretty much impossible with what I do. She took the cake today though, when she to horn in on two conversations I was having with other people.
First, I'm talking to Boss about an issue that I have. A company has processed something incorrectly, and as a result they are overpaying us by something like 3x. Putting that into the system is screwing things up, naturally, and we're discussing how to input it, what I need to do as far as notifying the company that screwed up, etc. Helpful Coworker hears something about "I can't unapply the payment in the system..." and calls out, "If you just click okay, it'll let you unapply it". Boss looks at me, I tell her I already tried this and it wouldn't go through. I call out to Helpful Coworker, "Nope, tried that, doesn't work.". Helpful Coworker comes over and spends 5 minutes telling us how she thinks we should solve our issue. Only problem is she doesn't know what our issue is. She assumed it was a completely different issue and was giving us tips for solving that. Once she stopped talking, Boss said in a very annoyed tone, "That's not what we're working on". Helpful Coworker says, "oh, okay" and wanders off. Totally clueless.

Second, I'm talking to Other Coworker about a payment issue she's having (all our bank deposits came in today for some reason, so we had tons of payments we were working to match up with our system). The company is telling Other Coworker that A and Y should be billed together, so they're not going to pay for A. Helpful Coworker comes over and says, "No, those two are billed together, so you need to void one." Other Coworker and I look at her in confusion and Other Coworker says, "No they're not, that doesn't make any sense!". Helpful Coworker says, "Those two are always billed together. If you see X and Y together, you have to void Y!" I said, "But we didn't bill X and Y, we billed A and Y." Helpful Coworker blinks and says, "Well, of course those aren't billed together. You need to get that fixed!".

She needs to stop trying to "help" everyone and just do her own stuff. Gah!