Many people so use Zupreem and are happy with it. Remember that not all rabbits do well on all foods. If your rabbit does well on Zupreem and you can get is easily and afford it, then stick with it. If your rabbit does not do well, then look into other foods.
It would be best to have what she was eating before you got her to help her adjust to the new food. If you can't get it now, you should slowly introduce the Zupreem. Start with a small amount, about 1 Tbsp, and increase that every couple of days as she gets used to it.
With rabbits, you don't want to be switching pellets often. It is best to find one pellet and stick with it unless you need to change. There are people with mix several different brands, but they feed the mix and aren't switching brands every month. This can be good if your supply is limited or you can't get one brand some times.
If money is an issue, you can try a feed store brand. A 50 pound bag costs about $15-20. You might want to freeze some as it will last a while with just one rabbit. While these pellets might not be the absolute best, they are better than the mixes with seeds and other bits and still have the vitamins and minerals needed.
Make sure your rabbit does get lots of hay. The brand and type doesn't really matter and you can offer a variety of hays. The hay should be green, smell good and not be too dusty. You can buy bales form a farmer and some feed stores do carry it as well. A bale costs about $4-10 compared to a bag from a pet store that can be $10 and up for about 5 pounds.