UPDATE - I have confirmed that the stock rim width is 5.5 inches. You can safely go to a 6 inch wide rim with the stock P195/65 R15 tires.There are 3 "stock" tire sizes depending on the trim level, 15", 16" or 17".
I'm assuming she has the steel wheels with wheel covers, then she has 15" tires P195/65 R15. You can confirm this by looking at the tire or the sticker on the drivers door post.
The other info you need when looking for after market wheels is the width of the stock rim, bolt pattern, hub diameter and wheel offset.
I'm not 100% sure of the width of the rim but it will be either 5, 5.5 or 6 inches.
Bolt pattern is 5 x 4.5" (114.3mm), hub diameter is 67.1mm and offset is +48mm.
you can vary the offset with other wheels from about +38 to +52mm. The lower the offset, the more the wheel will stick out past the fender. Remember though that 10mm is less than 1/2 an inch.
Before buying any rims, have the shop test fit on on front wheel to make sure it clears averything.
I hope this helps.