You have caught the guilt complex germ... we all have it at times.
Instead of assuming she won't appreciate you doing that... think about this
Do you appreciate her not sending you the money when asked and making you worry about how to ask her. Do you think she is worrying about that. I can tell you, she is not. So why should you.
I find its very useful when you hear yourself saying things like I'm worried she won't appreciate it if ... and flip it round. Also to ask yourself, would I behave like that? You are stressing yourself out worrying about the feelings of a person who clearly doesn't deserve all this anxiety.
ARe you worried about the next time you meet her that she will look askance at you? Brazen it out. Act as though it never happened. You never had to ask her several times to repay you money she owed you but delayed sending. That way you will be saving both your faces and can carry on.. but avoid situations where you have financial dealings again.
You say its not for financial reasons so that takes away about 98 per cent of the guilt for asking again. So relax.
She's either overwhelmed and has genuinely forgotten,
or Disorganised and can't remember where your text is or where the bank details are, - both of which she'd probably be grateful for the reminder.
Or
she's too lazy to stop what she's doing, get her phone out and send the money...
or she's hoping if she delays enough, she's noticed you appear to be a soft touch and hopes you will stop asking and she won't have to pay you...
For either of those last two excuses she deserves to have you turning up at your door with a rictus grin and big sign that reads PAY UP and displaying your bank details.
Who is going to think you should just let someone off £40 from a night out for now reason or that you are somehow mean to recover your money?
So what have you got to lose by asking her again?