Medicare no big deal

This lady holding a child in her arms interrupts me whilst i'm serving another customer.

Mother: Excuse me, I've got a script to be filled.

Me: Yes, you'll need to take it in at the prescriptions in counter overthere.

Mother: Yeh but there's noone there.

Me: Someone will come and assist you when they are free. 

So I end up dispensing the script for the child. Upon entering the name, the child's name did not pop up on our system. New patient. So I ask the mother, who was holding the child, for a Medicare card as her name was not on the system.

Mother: (gave me a dirty) Look I don't know what the big deal is, you should have all the details on the system.

Me: The deal is, her name is not on the system, hence why I need a Medicare card.

Mother: Omg, all the details are on the prescription. 

Me: No its not. The doctor only wrote the name. There's no Medicare or Address either. 

Mother: Well my daughter's sick and we've been waiting for a long time.

Me: Well, most people who walk into our pharmacy are sick but everyone still patiently waits. (me smirks) 

She says nothing. She later decides to take a jab at my other workmates. An item didn't scan at the counter so had to ask for a price check.

Mother: OMG, now i'm gonna wait a WHOLE YEAR for you people to check the price.

Assistant comes back and overhears her: That was $4.90 and no it did not take a year! (walks off)

Lady purchases for items and leaves.

What is wrong with this lady?