two females

Question
I have a female gsd who is 7,and was thinking of getting another female gsd puppy, would they get on together when the puppy got older.

Answer
Generally opposites get along better.  There has to be an "alpha".

So depending on the personality of your female, if your female is dominant by nature, then I would consider a more submissive female.  

I would also consider spaying your new pup early.

Good luck!