Maybe she's freaking about all of the responsibility that comes with success.

Sort of how Walter walked away from Gray Matter when he was in college after he met his girlfriend Gretchen's family.

In the first scene Jimmy gives his assistant a business card and says"

"when the cops question you give this person a call - tell them Jimmy referred you."

I am thinking that is Kim's card, and this episode shows how she was transitioning into defense law.

If it is her card, they must still be on good terms - given the gravity of the situation Saul is in.. I would doubt he would give his assistant (who saw him shred documents, pile cash into his suit case, etc... a lawyer's card who he did not trust or who liked him.

Yeah, during BB, Jimmy and Kim may not be a couple, but they could very well be friends and on good terms.

The only issue I see with that is that she also worked for Kim, so why would Jimmy say "this person"?

I thought for sure the card was for Howard Hamlin who she would not have known.

When are people going to smarten up and realize that Kim becomes "Wendy"

I also think it's a higher probability of it being Hamlin at HHM. Reason being: He would have just said go see Kim. I think this episode sets up a lot of different outcomes though.

Both Kim and Jimmy hiding what they are doing from each other.

Jimmy becoming shadier, Kim going more into public service/defense law.

Hamlin losing his grip, and perhaps his business falling apart. I don;t recall seeing if Chuck cashed Hamlin's check.