Bride: I expect money in my wedding card from you!
Guest: Sorry, I won't be able to attend the wedding. [doesn't send wedding card/gift, either]
Well, that's one possible way to handle it, anyway. Sometimes it's very satisfying to call someone out, but I don't think I'd do it personally.
ETA: I followed the link and read the actual story, and now I'm just kind of confused. Maybe it's because I don't understand text-speak? In the big blue bubble, from the slighted friend, I thought she was actually a little snarky. "Had I known that four parties were going to be held in your honor this year, I would have saved [the money] all up and given it to you in a lump sum..."
Point 3 I just don't understand. The bride says, "Ok but it's still something instead u coming for free ya know." I'll take a gift instead OF you coming for free? I dunno, some people might read that as joking.
Point 4 could be read as the bride/mom-to-be trying to be considerate of her friend, albeit in a ham-handed way--"You just said you're tight on money, should I not add to your pressure by inviting you to my baby shower?" I see threads here often with people asking basically the same thing--should I invite or not invite my cash-strapped friend to a gift-giving occasion? And most people suggest they be invited, I think, but obviously this answer is not always apparent to well-meaning people.