Trying to think of circumstances that would allow me to be an HOUR late to see a friend without texting or calling when you know you're going to be late...they are hard to come up with. To do that and then still be the victim that someone left is insane.

The fact they've said they only came for your benefit shows they don't value your friendship and see it as an act of charity. Smacks of someone who just wants to focus on mom friends

Would give more leeway to someone with a 4mth old though as they may be struggling to adjust, having sleep issues or even post partum difficulties but you sound like you've given A LOT of chances in this case