My kids had playmates (boys and girls) who went into hysterics too.
It drove me nuts.
I used to tell the kids, including my own, that if there was going to be screaming like that, somebody better be bleeding.
Crying and pitching a fit like that for messing up jumping rope or something equally ridiculous...no way.
If the screamers wanted to come over, fine, but I told them the minute I heard crying, they were going home because I wasn't going to listen to it.
I don't think you should spend a minute feeling humiliated and your daughter doesn't need to either.
A kid throwing a hissy fit like that, even at their own house, would have been my cue to leave anyway. I understand you like the mom, but if you leave every time, maybe she'll get the message that other people really don't want to hear it. Especially if people are going to look at YOU like "what are you going to do about it?"
In my opinion, you did the right thing, and left.
We're not talking about little toddlers having melt downs because they didn't get a nap and I'm assuming they are otherwise normal healthy children.
Their mother is probably used to hearing their fits and it doesn't bother her.
That's fine.
I love kids, I'm pretty patient. But the repeated freak-outs over nothing? No thank you.
It's not meant in a rude way.
If someone ever told me their feelings were hurt because I sent their kids home or my kids and I left because their kids were screaming, I'd be sorry for hurting their feelings, but the screaming hurts my ears so I guess it would have to be a wash.
That's just my opinion.
Like I said, be up front with the kids, ALL of them so it doesn't look like you're singling anyone out, that the minute someone starts crying like they've lost a limb or something, play time is over for the day. Follow through every time. If you're at the mother's house and they start up, just say maybe you can visit some other time and go home. You've already done it once. You might as well make a pattern of it.
Serial criers will cry whether you and your kids are around or not.
The only difference will be that you don't have to listen to it.
No offense to anyone. Again, just my opinion.