M.R.
Honestly, you should ask the hostess if she'd like you to hang around and help out- after all, you have a child in that age range, you know how hectic it can get!
Then you can follow her cues on whether you need to stay or go find a quiet place to read.
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The only time I'd ever insist on staying after the hostess says "go" is if you have a funny feeling, like the place isn't safe or if it just gives you a weird vibe.