This may be the first one where I don’t really have a definitive rating, but I’ll go ESH. Mike and Sandra probably shouldn’t have gone to the gathering after the stressful events of the day and should have politely rescheduled, and no one’s grief or stress or whatever warrants acting out in that way.

That said, you also suck for agreeing to host a child under the admittance you “aren’t good with kids”. You need to understand that the whole “go to bed hungry if you don’t like my food” is abuse. You were abused, and now you’re perpetuating that with a child that isn’t yours, and that’s absolutely inexcusable. I agree with other commenters that you aren’t obligated to fully cook another meal but you, as the host, should’ve attempted to offer a low-stakes alternative for the child such as a small sandwich or something because you agreed to host the child.

I also feel the “maybe they’re lying” comment is… weird. Do you not trust your friends? Do you need a picture of the hospitalized mother to believe them? It’s a very callous thing to say.