one of my 7 weeks old gerbils died. her sister has become un

[sima1]

We took her to the vet who gave her a painkiller and hydrated her she seems to almost completely recovered after a day. Should I get a friend for her?

[crittercrazy]

I'm sorry to hear about your gerbil.
And I'm confused, what do you mean her sister has become un. . .?
Well, that depends. If she's only 7 weeks old, then it would probably be easy to introduce her to another gerbil and she would probably be happier that way, but not always. She could be one of those gerbils that are fine on their own, so you'll just have to watch her and see.
In general though, my advice would be to get a friend for her if you can.