Whatever you do, do NOT encourage this kind of bad behavior, it will only lead to more of the same.

 
POT SB's taking shots at you just goes with the territory in the Sugar Bowl and some of them are VERY good at baiting the hook. I simply tell them the truth, I have a "hard and fast" rule that I NEVER break and that rule is to never, ever "send" money to someone I have only met on the internet. I don't mind "giving" money in person, but I absolutely refuse to send money to someone who might prove to be some old fat guy sending messages from his mother's basement, pretending to be some hot young thing. lol

 
I would simply counter with, "If you really are in such dire straights, let's meet today instead" If she accepts, you are in like Flint, if she wriggles out of meeting she was nothing but a scammer in the first place.

No, you won't buy her a dress to wear on her date with you, but you will buy her used panties when she does show up.

 
You're absolutely doing the right thing by ignoring or declining these requests. Chances ar slim and none that any of these SBs will ever go BCD with you.

You have to have a thick skin for this and for life. Set your rules and do not deviate.  If that’s what you want, eventually a 20 yo will come through.  The odds support this fact.

If you start sending money it will never end, plus you are not gonna get laid either.   My line about us both being motivated is effective.   This activity truly requires some patience and persistence as well as some game.  The outcome is never certain, so you really need to learn to enjoy playing the game.  Otherwise the routine disappointments will drive you nuts.  As for 20 year olds, there's a new crop every year, right?  And some percentage of them are going to find their way to SA and some percentage of those will find their way into your bed.  I had a coffee date with yet another 20yo last week and am scheduled to have my first BCD date with her tomorrow.  I don't "expect" anything, but I "hope" she'll jump my bones!

is a total time suck.  Some here have gotten very efficient and scientific with their searches and can separate the wheat from the chaff without too much effort.  Others seem to get strung along, but even finding the good ones still requires a time investment, so there is a temptation to "settle" for less than you deserve just to get off the merry-go-round.  You must be diligent and heed the red flags when they appear.  

 
SB's know that control of the relationship is vital to extracting the most money possible out of a SD, so these little nickel and dime tests tell them whether you are the controllable type, or not.  If it looks like they are not going to be able to be in control of the relationship, they will usually not meet with you in the first place if they are a scammer.  Not all SB's are this way, but for every one who plays it straight with you, there are three or four who are going to try to hustle you for whatever they can get, even a lowly Uber fare.  Its a type of conditioning of you for when they want to go for a more substantial amount.  The British have a saying, "In for a penny, in for a pound," but if you have this attitude with SB's, you're going to get hustled.  Know when to cut your loses (including your time investment) and get out before you get hustled.  There ARE SB's that will make a deal and stick to it, but they are in the minority, in my experience.  Those are the ones you need to find.