It's ok, it's better to let the fry be eaten than rush into buying stuff, I would just let them be this time and let nature take it's course. Your best for sure bet is to make the mops like Dino said and to go out and buy some dense fake plants for the babies to hide in. I would also once the guppies are skinny all of a sudden crush up some flakes so the babies can eat too. I would wait and look around on ebay and cragslist.com or at your
LFS's for a sale and get as large of a tank as possible. If not you can buy a 10 gallon and make a divider, post in
betta board to make your own and divide them and do what Dino does on a small scale. I would get a sponge filter for both sides and cycle your tank and then put your next guppy fry in the tank.
Dino feel free to correct me or add anything please.