Sylvia: sorry to hear about your bereavement...
First: as a stop-gap measure, your 'onboard' graphics should still work. Rather than be without a PC, have you tried plugging your monitor into the other VGA output - the one that your PC would use if it didn't have a graphics card? It could be that your system will automatically revert to that - or you may need to uninstall (both logically and physically) your Nvidia card.
Second: I think Dell fitted a number of different graphics cards to the 9200. In fact, almost any graphics card should work - and could be fitted by anyone, perhaps even your nephew. It's not hard. Failing which, your local computer shop could probably do it for free if you bought the card from them (but you'll pay more for the card than you would online). For sure, Dell don't have to be involved.
Third: your machine should have a 'service tag' stuck to the back. It's probably 7 alpha and numeric characters. If you go to the Dell site support section, entering your service tag may well give you more information about what your PC was configured with.