It's a spaceship. It's questionable whether knocking can even be heard from inside.

Well, they can slowly fly around and try to get noticed by her sensors.

It's really hard to tell through an opaque ship whether the occupant has noticed you.

She has an airlock which she can open if she wants to talk with them.

Yeah no.

Eventually he runs low on air and goes back to his ship.

She has been hailing him.

There are some screens blinking but it takes him a while to figure out what they mean. It takes him even longer to send the same thing back.

And then she says, "This is the Federation starship Prometheus, how can I help you?"

And now he has Anitami-to-Quenya here to figure out the ship and Anitami-to-English here to figure out what she's saying. It takes a bit.  

"Noticed what you were doing. Don't work for anybody, haven't told anybody. Some people might notice the way I did but they don't work for the Federation or care about its rules."

"I'm doing a deep space survey."

"Not what I meant."

"If this system belongs to you I'll be more than happy to get out of your way."

"I do not know of anyone with a claim on this system."

"I see, thank you for clarifying."

"It seems like a safer thing to do from outside the Federation."

"I'm not sure this translation is very good."

"Do you have English," he says to the fairy. 

       "Yeah."

"Have a confusing Elf-to-person-without-a-chip interface." 

      Fairy floats it over. 

"Getting a different translation solution now," he tells the mysterious ship captain.

      And then another voice says in perfectly normal English - "Is English your preferred language?"

"...that or Vulcan."

        "Let's do English."

"...okay."

"We have a means of remotely monitoring star systems and have for some time been doing that with the intention of figuring out a productive way to give low-tech civilizations warp."

"...I'm really not qualified to make first contact, would you like me to direct you to my government -"

"No."

"...okay..."