yea man. thats normal. the bigger she gets, the more leaves towards the bottom will wilt. if you look at a freshly harvested plant it does the same. the reason behind it is because the plant is using the nutes from within the plant. when it exhausts one leaf, that specific leaf dies. your plant is telling you that it is no longer trying to "fight" to grow, now shes gonna work on gettin tsller snd more msture so she csn bud. post some pix, but everything sounds ok, chill and light one up and blow on her...