jack of all trades???

Told customer that i cant do any additional sewing for her as my workers will be knocking off in 10 mins.

Customer then asked me" cant you sew it for me???"

What the... Am i supposed to know everything cos i work here?
I admit, i am not in such a good mood cos my nose is blocked and i feel so sick from the cold. So my reply to her is " if you can sew it, i might be able to sew it".