can my partner go to premium locations, like sandboxs and will she be able to use them as well

[RonJG]

I have a premium yearly account it did not seem to make sense to take out two accounts at the time but was wondering can she also use the sandboxs and other premium sims? 

If not on her own can I take her to some as my guest?

[valerie Inshan]

If she is not a premium member: no. Not even as your guest. The only "premium" place where you can invite her is your Linden home if you have one.