Offending an old friend - AIBU?

Your life ... you have tried can't do any more ... enjoy yourself ... her loss ... wait until & if she contacts you .... harsh I know ... now ... go out enjoy yourself with your other friends

I quite understand that you would arrange to see groups of people first as this often takes some coordinating whereas a single person can more easily arrange a meet I would have thought.
Leave it up to her. If she wants to see you she will get back to you.

I agree with Grandmabatty. Except that I'd offer a couple of dates & then just leave it at that. If your friend can't make either then I'd give up trying; IMO life is too short to keep making an effort with "friends" like this.

If you see also thinks of you as a very close friend then I can see why she is miffed that you didn’t make arrangements to see her first and fit the others around it. I don't think she is a very close friend.

Is she offended because you planned in advance to meet others but only contacted her when you arrived? Does she interpret this as an indication you value her less?
GMB’s suggestion to offer two dates and then give her the opportunity to arrange a time is worth pursuing imo.

I had this when I used to return to Holland. One friend made me feel guilty if I didn’t prioritise her on my visits. She has since died and to be honest it has made things easier.
I just used to ignore her sulks.

I think you've done as much as you can to keep the relationship going. If you still want to see her, offer her a choice of two dates which pins her down. If she says neither suits then ask when would suit. If she doesn't reply, I would leave it in her hands.