is it necessary to invest in a play yard?

Not necessary per se, but a good-to-have. My cousin has a play yard for my niece to play in. My cousin would keep most of my niece's toys within the play yard so that there is less clutter around the house. She sometimes joins my niece in the play yard. With a cushion and a book, they could comfortably have a reading session and some quality mother and daughter time. My niece is used to playing by herself in there, my cousin often could do some household chores without having to worry about my niece's safety.