Am not comfortable discussing money esp when it's owed money (to me).
OH is away at sea for a lot of the yr (this yr). His DS asked to come to stay for two weeks in summer hols so I booked and paid for his flight and his mum (through him) offered to go halves which I accepted (my OH and I do not have shared finances as he lives on the base when not at sea).
No more was said. I emailed her all my contact details in case she didn't have them thinking she would reply with hers and possibly ask for my bank details so she could transfer the money. She did not even reply. When DSS arrived I figured he may have the money in cash, he did not.
When he left (I had no contact whatsoever with her during his two WEEK stay) I sent a note saying thanks for letting us have him and offering to go halves if it's easier for you could you please transfer the money online/at your local branch, here are my bank details, and still nothing?! 
It's over £100 and at the end of Aug I was struggling (ie I had NO money and 3 uniforms to buy - had to borrow from my DS to put petrol in car to take DSS to airport.
It's been over a month now.
What do I do?! Let OH sort it out when he gets back and risk bad feeling, or just leave it?