AITA for making a mutual friend pay for her share of a trip that she didn’t attend?

<div class="_2TO-components-SimpleRichTextEditor--paragraphElement" data-block="true" data-editor="855eu" data-offset-key="77s0i-0-0"> <div class= "public-DraftStyleDefault-block public-DraftStyleDefault-ltr" data-offset-key="77s0i-0-0"><span data-offset-key="77s0i-0-0">It's the listener submish episode!</span></div> <div class= "public-DraftStyleDefault-block public-DraftStyleDefault-ltr" data-offset-key="77s0i-0-0"> </div> </div> <div class="_2TO-components-SimpleRichTextEditor--paragraphElement" data-block="true" data-editor="855eu" data-offset-key="7vp7c-0-0"> <div class= "public-DraftStyleDefault-block public-DraftStyleDefault-ltr" data-offset-key="7vp7c-0-0"><span data-offset-key="7vp7c-0-0">First up it's</span> <span data-offset-key= "7vp7c-0-1">A</span><span data-offset-key= "7vp7c-0-2">I</span><span data-offset-key= "7vp7c-0-3">T</span><span data-offset-key="7vp7c-0-4">A</span> <span data-offset-key="7vp7c-0-6">f</span><span data-offset-key= "7vp7c-0-7">o</span><span data-offset-key="7vp7c-0-8">r</span> <span data-offset-key="7vp7c-0-10">t</span><span data-offset-key= "7vp7c-0-11">e</span><span data-offset-key= "7vp7c-0-12">l</span><span data-offset-key= "7vp7c-0-13">l</span><span data-offset-key= "7vp7c-0-14">i</span><span data-offset-key= "7vp7c-0-15">n</span><span data-offset-key="7vp7c-0-16">g</span> <span data-offset-key="7vp7c-0-18">m</span><span data-offset-key= "7vp7c-0-19">y</span> <span data-offset-key= "7vp7c-0-21">r</span><span data-offset-key= "7vp7c-0-22">o</span><span data-offset-key= "7vp7c-0-23">o</span><span data-offset-key= "7vp7c-0-24">m</span><span data-offset-key= "7vp7c-0-25">m</span><span data-offset-key= "7vp7c-0-26">a</span><span data-offset-key= "7vp7c-0-27">t</span><span data-offset-key="7vp7c-0-28">e</span> <span data-offset-key="7vp7c-0-30">h</span><span data-offset-key= "7vp7c-0-31">e</span><span data-offset-key="7vp7c-0-32">r</span> <span data-offset-key="7vp7c-0-34">b</span><span data-offset-key= "7vp7c-0-35">o</span><span data-offset-key= "7vp7c-0-36">y</span><span data-