wasserball wrote:I forgo to mention that she only want to take photos when there are 2 or more people. Will that make a difference in the recommendations?Yes it does as subject greatly influences what lens is most optimal. Many lens recommendations made by you and others, are now poor choices. Do you have any other shooting condition information, you may have forgot, that may have an impact? Does she plan to only shoot on bright sunny days, for example, and not venture indoors?Will the D90 make better photos than the D3100 in that situation?Depends what lens you have mounted on each camera.

of the D90 with the 18-70mm which one other recommended as well.  Now, without much fanfare,  what used Nikon DSLR camera and lens would YOU buy if you had $400.  The question is very clear.