Robert
The IIci was intended by Apple to be capable of work as a server, as is demonstrated by the provision to lock the AC power switch for autorestart after power restoration. Before the arrival of the IIfx, which was aimed instead at the graphics world, it was the 'wickedest' Mac in Apple's line-up.
I bought a IIci recently, principally for the excellent condition of the case, and what proved to be a good power supply, free from trickle-voltage problems. It now has a 'new' logicboard with decent metal RAM clips, together with a 50MHz 68030 DayStar PowerCache card, an Asanté NuBus NIC, a Radius NuBus 24AC video card and 8 x 4MB RAM cards. Add a cleaned-up floppy drive and a 4.4GB IBM HDD (partitioned 500MB and 3.9GB) with OS 7.5.5 on the smaller partiton, and boing! it was up and away. It drives an Apple MultipleScan 14-in AV display or a Mac Portrait Display (256 greys) according to the need of the moment, and, thanks to the video card, offers millions of colours. ('Vampire Video' is no longer an issue.)
The IIci could be hacked to run OS 8.1, which it would do without a hack if it had a DayStar 040 (instead of the 030), or easily up to OS 8.6 or 9 if it had a 601 processor upgrade. In your case, however, it will be much more advantageous to spend almost nothing on the IIci now, and devote the money to purchase of a beige G3 desktop or minitower, which is cheaper than chips. It will have the advantages of running your wife's software natively, of being able to exchange files with the G3 PB, and of being upgradeable to OS X if that is useful to you. Then you can treat the IIci as a fun machine, even if that means as the server to the other machines.