Am I Legally Responsible For A Former Friend's Unused Flights For A Planned Trip Together She Dropped Out Of After I Changed My Mind About Lending Her More Money?

EDIT: shortened because previous version was a novel

I’m trying to recover $1400 from a now former friend I lent back in April. She’s refusing to pay back the full amount by claiming I’m responsible for her unused flights from a separate incident.

Earlier this year a mutual friend invited us to Europe. My former friend said she would need me to front the hotel costs if she stayed as long as me. I didn't give a definitive answer. Despite this, in later conversations she seemed committed to going for the same length.

While planning the itinerary, I ask her to book some on her card. She says she won’t be able to do that but assures me if I front all the costs, repayment will be quicker this time around. I half-heartedly agreed but stress the timeliness.

After adding up the costs, I ask for a schedule by the next day. When she doesn't provide it, I consider her existing debt and past behavior and change my mind to front the money. She either wasn't willing to use her own money or find alternative funding so she dropped out completely.

Now I'm asking for the $1400 back and she's claiming it's my fault she couldn't go on the trip and use those flights and therefore will only pay me whatever's left.

I don't imagine us ever getting to a place of agreement so my plan now is to file in small claims court. The question I have is whether she has a strong argument.