I stupidly lent a fairly new friend £50 about two months ago. I know her through the gym I attend and she gave me a story about her and her boyfriend not having any money as he'd been off work and she was between jobs.
For various reasons, she has turned out to be a using cheeky fucker. She now has a well paid new job and despite repeatedly saying for a month that she was going to pay me back, she didn't and has now gone quiet about it. She mentioned at one point that she would pay me back £2 per week! 
She has, during lockdown, repeatedly put pictures on her Facebook of new things she's bought online; clothes, shoes, make up. She also sent me a FB message a few days before lockdown to show me photos of the new haircut and colour she has had done!
I don't technically need the money but her cheekiness is pissing me off a huge amount. I'm unsure of whether to a) message her via FB or text and tell her she needs to PayPal me the money ASAP. She is so self absorbed and dramatic that she will no doubt think I'm horribly unreasonable and being mean to her and will fall out with me. Or b) do I just write the money off and just have nothing to do with her again, ever.
Either way is going to be awkward for me as the gym is a very small, close knit place and we are all friends and often have nights out so it's going to cause an atmosphere.
At the moment it's just winding me up so much and for my own peace of mind need to do one or the other.