@GuldTuborg is spot on.
Another approach would be to, rather than adding in the fermenter, to add the spices to the boil. That is pretty standard for Belgian Witbier brewing.
Regardless of which method you use, if it were me, I wouldn't add the ginger at all, as mentioned above, that's a tricky spice to use in brewing. For the orange peel, there are two types that give very different flavors - if you mean the dried orange peel you can buy at homebrew stores, that will add bitterness to your beer. If you add fresh orange peel, like orange zest, that will add citrus and sweetness.
Another spice that your wife might enjoy is coriander seeds, crushed and then tossed in the boil. Coriander seeds used in that way tend to give a bright, orange-like flavor.