unsure how i should interact with my daughter

okay so alot of people tell me my 4 year old daughter is very grown up..now im wonderng if thats because im too hard or somthing. i discipline when she needs it i laugh and joke with her we read books and play together. i had her when i was 17 really young and unsure of how you parent. today i still learn but im feeling like im unaffectionate with her. id like to know if anyone who has had post natal depression had trouble bonding with their child and if so have they overcome that and how did you do it....