I've never had step throat, so I'm not totally sure what it is, can you get rid of it with medication? Is it like having a cold?
You never know, it might not even get that bad (again I don't know what it is).
Yes it's the weekend and nobody likes to get sick at the weekend, but are you sick? You have a cough and sore throat but you can probably still enjoy your weekend, can't you? I wouldn't cancel any plans unless you were feeling really rough.

Don't beat yourself up about catching her illness, how were you to know?? You didn't know, it wasn't intentional, even she didn't know.
My friend once came round my house with SCABIES, sat on my bed and everything, even hugged me. I told my mum when she left and she was like "OMG!" I was due to leave the country for 3 months in 2 days time lol. Had to disinfect everything, spread expensive cream over my whole body "just in case".
These things happen. You're not an idiot!!

xx