I cannot fathom how many posters, think it's right for CF to be reimbursed as she's out of pocket?!
Friend's boyfriend buys 2 tickets for gf's fave band. I get chosen as +1. I get to see the band for free. I happily pay for petrol/parking.
Out with friend for lunch, she has a voucher & insists on paying for us both. I then pay for drinks.
Friend didn't pay anything, so EXACTLY same context in all scenarios, including the OP's.
Work have specifically given OP a perk, for her work. ( It has been paid for, just not by op ) Friend didn't have to go, but to then ask for half of petrol costs to arrive at the place, where everything from then on is free (an all paid expenses weekend away) is beyond rude and grabby.
It's basic manners! Courtesy ! what a reasonable person would do, to show thanks!
OP ignore the text for now, she will know you've seen it. See if she has the bottle, knowing you've ignored her request to ask again. Then pick a reply from the funniest replies above. Do let us know any outcome.