Hi B.,
I don't mean to be rude, but I think you are reading way too much into this! I think you are being rather hard on this mom, when since you are a mom you ought to be able to understand how crazy life gets and how daily plans don't always go how they're supposed to. In my neighborhood the moms TRY to meet at the park once a week - some weeks, lots of moms show up, and other weeks it might just be one other mom and me. One week I was the only one who showed up. Many weeks I have said I'd be there and then my baby has decided to nap at that time, or our fridge is empty and I realize we have to grocery shop instead. I think moms are all doing the best they can and life with kids can be crazy. I think you'd be better off letting go of some of your paranoia concerning the whole LDS issue, also. I am LDS, some of my best mommy friends are not LDS - it has never been an issue for me. I will be friends with women who I click with and who have kids that click with my kids, regardless of religion. Chill out, momma!!
p.s. - Practically every mom I know drives a minivan - the van you saw was possibly not your friend's van...