i don't have any experience personally with satelite internet. Although i have talked to a lot of people who say the speeds suck. I used to work tech support for Alltel on their broadband cards and such. I talked to many people who ditched satelite for a broadband card because they could not get DSL or cable. But your provider might be different.
But i think the equipment you're looking for is a mobile broadband router. If you go with one of these it will allow your card to connect and stay connected, then you can share out your connection via wired or wireless connection. Here's an example of one by Kyocera, it'll support certain USB type cards, certain PCMCIA cards and a few PCMCIA Express cards.
http://www.kyocera-wireless.com/kr1-router/
The key is to make
certain you get a router that will support your existing card. It's pretty simple how they work, pretty much insert your broadband card into its respective slot. log into the router, the manual should give you detailed info how to do so. Then you go to a screen and setup things like your cell number that's associated with the card, a password, possibly a username and hit connect. once it makes a successful connection to your provider you can either plug an ethernet cable into it or you can use wifi and configure a password if you want. most people i helped set these up lived so far away from their neighbors they didn't setup a password
Another thing to think about, is what the router will support. There was 1 router i saw and i cannot remember for the life me of who made it; but it would support a mobile broadband connection, cable or dsl. So if you were ever in a situation that you could utilize cable or dsl this particular router would allow you to do so. On the other hand, the Kyocera will only support a broadband connection (at least as best as i can remember).
Another option would be to use Internet Connection Sharing (ICS) as mjonesjr said. The downfall to this is your computer would be hosting the connection, so if your computer was off or not connected your wifes computer would not get online either.
But if that was the case, maybe she could use your broadband card since you would not be?... The upside to ICS is it wouldn't cost you anything more than an ethernet cable..
your cell provider should be able to give you details about what mobile broadband routers they sell and what they're compatable with. also, you should not have to sign a contract to buy one of these. the contract should be on your wireless devices. so you could buy the router off ebay as long as it's the right one.
oh ya, and a misconception about mobile broadband, its speed tests may peak at 1Mb/sec or so(maybe higher), but the power of the cards are pretty weak. If you're just going to surf the web, watch a video clip or something that'll be ok if you don't mind it taking a sec to stream video. But if you're planning on using xbox live or downloading hundreds of megs from torrents then you'll have a poor experience.