Your sister will need a lot of support, without the dad there (because she's living with you?) she will need help with cooking/getting groceries, people to spell her off with holding the baby, maybe even help with night time feeding, help with laundry, medical visits, help getting baby stuff, help recovering from the birth etc. The floors in your home should be clean and safe, babies and toddlers spend a lot of time on the floor, furniture should be fastened to the wall, some babies/toddlers are climbers, any hazards in the home like exposed wiring should be dealt with, as soon as babies are mobile dangerous things need to be put away or locked away (knives, cleaners, batteries, detergent, pet food, medicines, soaps etc) Babies will pull at cords or tablecloths and put themselves in danger, lamps, Tvs, irons, kettles etc. and will put any thing within reach into their mouths. If you have stairs you will need baby gates. If you live on a busy street you've got to be vigilant about toddlers getting out on their own, maybe even putting a lock at the top of the door if need be. Keep in mind babies chew and suck on anything within grasp or leaning distance and when mobile will pull at things to get themselves up, and eventually will try climbing in and on things to reach stuff like drawers, cabinets, dishwashers, stoves etc. Oh and think about where toddlers heads are, often at table height, I found head injuries happened a lot in the early walking stages, I got rid of a concrete table we had.