So I was told by a family member that I need to play with my newborn to help her development, but how do you "play" with a 5 week old?
5 week olds really just eat and sleep, but when my boys were up for longer times, I would sing to them, talk to them, play music and dance. My youngest is 2 months now, and when my oldest (20 months) lets me, I'll lie down with him - sometimes both of them- play peekaboo, tickle them.
Personally I don't think it really affects development until later (4-5months) but it keeps me sane. Otherwise you go crazy. I got a lot of creative side work done while my kids slept.