"Nosotras vamos allá."
Traducción:Noi andiamo di là.
Hello, with "di", it adds the meaning of "in there", "over there" For instance, you are in one crowded room and ask your friend to go in another room where it's more quiet and you can talk. "Andiamo di là" = let's go in there (that room) It can also mean "in that direction" "Noi andiamo di là (while pointing)" --> We are going in that direction.
"Noi andiamo là" would mean simply "we are going there"
Hope I made it clear enough!