First off, if Yaddle had trained Luke rather than Yoda, then Frank Oz would have used his Miss Piggy voice instead of his Grover voice. Here's how the dialogue in "The Empire Strikes Back" may have gone...

THEY MEET--

Yaddle: Help you I can, find your girlfriend.

Luke: I'm not looking for my girlfriend I'm looking for a JEDI MASTER.

Yaddle: Hhmm. Well, I'll be in my cave when you decide to look for a girlfriend, hot stuff!!

FORCE TRAINING--

Yaddle: Through the Force, things you will see, other places...the future, the past, old friends long gone...Kermie!

WHEN THE X WING SINKS INTO THE SWAMP--

Luke: My ship!

Yaddle: It's no different from moving the rock.

Luke concentrates on getting the X Wing out of the swamp.

Luke: This is impossible.

Yaddle: Always with you it cannot be done.

Luke: Well, you get it out!

Yaddle: Moi? Who do you think I am, Yoda?

BONUS SCENE, "Return of the Jedi"--

Luke: Yaddle, I must know, is Darth Vader my father?

Yaddle: Your father he is. Go to him you must. Kill him and then come back here and take me to dinner--Kermie!!

Luke: For the last time, I'm not KERMIE!