What else do I need for my newborn as well as the 3 month old I'll be watching?

Why do people always kick you when you're down? I'm 37 weeks pregnant and I know a person who is about 18 and go back to highschool to finish for her diploma. She lives at home and will be moving out within a month and no one will help her watch her 3 month old baby for a month and a half so she can go back in Sept instead of Jan so she can graduate next spring. Her parents work full time and she's really having a tough time moving on to get her life on track because no one seems to 'want' to help her. She will be living on student welfare and can get subsidized daycare when she does get on her own, but they won't help her until she's on her own. I will be having my baby on Sept 15, but I've offered to care for the baby for free (she provides made up bottles, diapers and other things the baby needs) until the end of Oct when she can get the subsidized daycare in place, along with my 22 month old daughter. I am curious if there is anything else besides a swing, bouncy chair, playpen/binette and some baby toys, mat to play on with toys on it that I may need or any other suggestions/advice I could use. Thanks for any comments or suggestions. I know it's going to be hard, but if I can help one more person get a better start in life it's SOOOO worth it!