Here is a good webpage for piggie advice and tips for you:
Guinea Pig Care and Health Information
As for diet, she would be much better fed a pelleted diet of hard feed with added vitamin C rather than a commercial mix. But gradually introduce this. Hay is required 24 hours a day. Hay should be green in colour which indicates it`s quality.
The Zoozone will be nice for her to sleep in during the night, but if she`s allowed lots of out-time during the day, that`s great. Females usually like company (males are more territorial) so you might be able to find her a younger companion.
Fresh veggies is a good way of giving them their vitamin C aswell as having it already included in the pelleted food.
Lots of people set up small dog cage pens for indoor piggies.
Leave the door open during the day and close it at night. They do seem to be a nice type of caging for indoor pigs and bunnies if you want her to have ease of access to her bed and water bottle.
The link I posted is a really good informative site and also links to the wonderful Peter Gurney`s A to Z of piggy health.