I lived in Ostia for almost a month with two small children. I do not recommend this apartment for people with small children. The first thing our kids found when we arrived was broken glass in the living room, my wife had to pick up all the little pieces of glass and mop the floors. The hostess answered all our problems, sorry, and we had to solve them ourselves. Our stroller also didn't fit in the elevator (56 cm limitation for entering into the elevator) because the description didn't state a real width limit anywhere. Therefore, two adults are required to lift the child and the stroller. Several times we left the stroller on the first floor for a short time, it did not interfere with anyone, but someone stirred it anyway. In the apartment, almost everything is occupied by the things of the hostess, we did not have enough free space for our personal belongings. There are also many beautiful decorative things that were interesting for children, but also dangerous for them. The apartment is quite dirty, only the main surfaces are more or less clean, and the rest is covered with dust or dirt. A kitchen with ingrained dirt, and a strange smell, if you close the window, then it's hard to stay in the kitchen. Forks and spoons and utensils should be clean, but we had to wash them extra. The gas stove was also difficult to ignite, we spent a couple of minutes trying to turn on any burner. Hot water is also heated by gas, so the water pressure is weak and the temperature constantly changed from hot to cold, so it was quite difficult to wash the children. There are also sewage problems. We rested in July and it was very hot, even at night with open windows and running fans it was hot to sleep. The heating worked for some reason when it was +30 outside, maybe this is due to gas heating. There are two pull-out sofas in the apartment (however, the bedroom could have had a normal bed), after a few days my back and neck hurt a lot from sleeping on these sofas. I tried different options but nothing helped, so I do not recommend staying in the apartment for a long time. Also, the metal movable mechanisms of sofas are quite dangerous for children.
The location of the apartment is good, close to the sea where there are many paid and free beaches, many different shops and cafes near the house, also a train station is a couple of minutes walk, from which you can easily go to Rome. If you are by car, then there is free parking around, and a lot of parking spaces, but unfortunately they are all constantly busy, and it was difficult to find a place to park, you spend either a lot of time looking for a place not far away or you go far and spend time walking to the apartments.