You both had a game plan and roomate sucks. It is all on her.
I do this bs with my own family. I sit and watch the cats for free.
Meanwhile they go island hopping. This stupidity has to stop.
You gotta say no. You gotta say "pay me up front". You have to say
If anything 'happen it is on her. You both made plans and you never had any
obligation to play Nanny. It is like my dad with his mother. He will
literally drag his mother from her upscale apartment to his house to just
to be a free baby-sitter and even drop off my sisters and brother to her place
if possible. That is low and that is what your roomate is doing to you.
You and her like getting banged well babies from that. Now time to pay the piper.
You had your plans and she had her plans. If her plane is late that is on her.