Well, sadly, we've been there, done that.
A few yrs ago, my mom decided her one "wish" in this life was a family reunion. My sister, God love her, decided to use her DVC to make the dream come true. She secured accommodations for all 18 of us at OKW for the week before / including xmas. The crew included me, dh and our two boys; my brother, his DW and their son; my DVC sister and her DH and two girls; my mom, and lastly, my other, oldest sis and her DH and 4 kids. And therein lay the problem. See, brother, DVC sis, and I are all on comparable life comfort levels in this world, thanks largely to a hard work ethic, education, and fairly conservative living. Eldest sis has ALWAYS, and I do mean always, struggled with these concepts. We have all bailed them out to some extent at various times. This trip was no exception. A few months before hand, they had financial difficulties. My Mom bailed them out. Then a few weeks before the trip, her eldest son (barely a teen) was arrested for breaking, entering and theft... niiiiice. Again, my mom did the financial bail-out. THen, their washing machine died, then their car too -- so no means of transportation to WDW. My DVC sis and Mom called me, wanting to know if we could help bail them out. I said they could send me a utility bill, or such, and I would pay it, but no way would I send cash. I would pay for a rental car, rental washer -- or buy one from Lowe's or Sears and have it delivered -- but no cash. I learned a long time ago that cash would not get spent on what needed done... and you cannot put stipulations on cash - once it leaves your hands, it's literally OUT of your hands. In the end, Mom and DVC sis bought them a used car, and tried to put a stipulation on it -- under no circumstances could the breaking-entering son be allowed to drive it. Yeah, right. That's like closing the stable door after the horse is out. Mom said oh no, she had my sister's assurance -- they would keep that promise. According to my niece, however -- he drove the nearly the whole way there. THat put my mother's shorts in a wad, as you can imagine. While at Disney, we (the solvent siblngs) all tried to keep things in budget -- for example, we all took turns each night making dinner in the villa (rather than dining out). Guess who didn't show up for these quite often? Too busy at the park -- they grabbed food there. My DVC sis bought them their park tickets... but teen delinquent son decided WDW was "lame" and wanted to sleep in the room all day -- wasted his UPH. My DVC sis tried to spark some excitement into the teen crowd and took them all pool-hopping (and this was when SAB was included in the hopping); he pronounced ALL the pools equally "lame" and spent most of his time grabbing his brother's camera to take pictures of girls' backsides as they walked away. DVC Sis: Grrrr. In the end, the trip left us quite frustrated, because the efforts made to keep things cheap seemed for naught -- we were only saving our OWN money, not theirs. (Plus -- the teen son was truly obnoxious, disrespectful to his parents... I'd like to say it was a phase and that he later became a model citizen, but his story is a long one, filled with jail time, rehab 2X, and other sordid details. I only hope his next 22 years of life aren't nearly as colorful.)
Sigh.
The scenario of inviting folks who perhaps shouldn't go has since happened to us several times over. (We haven't learned our lesson yet. Color us weak.) It puts a lot of pressure on all involved, in the planning stages AND the trip... and even afterwards. My DVC sis probably still feels they weren't very grateful of all that was done for the other sis. Yet my other sis feels resentful that WE go to WDW "all the time". When financial problems for the invitees exist, it puts you in the situation of deciding whether you should compromise your own plans (in which case, if they then splurge on themselves, will you be irritated?) or simply forge ahead and keep your plans no matter the cost (and watch them spend money they don't have ... and feel like you're an accessory to the crime?) Not a fun place to be.
We recently had the experience of inviting family who, by all accounts, should have canceled, not due to finances, but health. They had a baby with serious medical problems. With each hurdle faced, we would make the offer -- It's ok, we understand if you have to cancel! And each time they would get increasingly vehement -- WE ARE GOING! Then another surgery would come up, or set-back, or even plans that they would bring on themselves (like selling their house and building another -- with closing set a week or two right before the trip!) and yet still they would answer -- WE ARE GOING! I was going nutso -- I just couldn't fathom planning a trip, with all that was on their plate. But go on the trip they did, and I will admit we had a good time, though it sure seemed tense at times. Turns out they had found out a few weeks before departing on the trip that they were expecting again (a BIG "surprise" -- she had sold ALL the baby stuff 2 months prior). I guess they figured that where vacations were concerned, it was now or never... (or at least, several months down the road!)
I don't say any of this to scare you -- and I really don't feel I can even "advise" you, because all families are different. What one family is comfortable in doing / saying, another may not be. The fabric of each family is all on a different weave! All I can say is I feel your pain, and I wish the very best for all concerned. My heart goes out to those kids -- you don't say what their ages are (or perhaps I missed its mention). Failing school has got to be a huge self-esteem blaster. And I can't even imagine being so blase' about their education, but then, that's spoken as someone who spent the better part of her life in some school, college, or university!
Let us know how it all comes out in the end...