The situation. An elderly woman has just died. She's Jewish (Conservative) and active in her community, but most of her family is already deceased, and she's estranged and geographically distant from the rest of them, with the exception of her six-year-old grandson, who she was raising at the time of her death. Also, the living relatives (who she didn't like, and they didn't like her either) are not particularly financially solvent; while they would probably be able to get the money together to send one or two people to the funeral/etc., it's unlikely that they would or could afford to all go.
My question(s). I know a bit about the immediate Jewish mourning practices under the standard (?) situation - funeral, sitting shiva, shloshim for thirty days after the burial, etc. When a parent dies, part of shiva is their children saying Kaddish for them. Does this apply to young children? What about grandchildren, if the woman's child (grandson's mother) is already deceased? Also, if the woman was living apart from her relatives, who would take charge of the funeral/shiva/etc.? Would the (distant, very much did not like this woman) relatives be expected to show up, if traveling was a great physical and financial inconvenience? Also, now that his guardian's dead, the kid is going to be shuffled off to one of said relatives. (Which adds to the financial strain of traveling, since they'd be paying for his passage, too.) As far as shloshim goes, would he be expected to observe that? Is it even possible to observe that in this situation? Or - because this is a distinct possibility - am I getting all of this completely wrong?
(Googled various combinations of "Jewish mourning" + "children" + "exceptional circumstances", and talked to a friend of mine, who's Reform Jewish. Sadly, she didn't know, and internet searches were similarly unfruitful.)
ETA: Thank you! You all have been extremely helpful.