Thanks for the advice.
Well, we got the bike ($360 from craigslist).
I understand your arguments, and may have screwed up, but I'm going to try a few options. If I can raise the handlebars by about 3 inches, then I can duplicate the fit of her current bike, with which she is very comfortable.
Although the fork is carbon, the steerer tube seems to be metal. The handlebars are 31.8 mm.
The current stem is angled down, and is very close to 90 degrees.
Check my math, if I were to get
this adjustable stem, the handlebars would go up by a maximum of
about 120 mm / 1.414 =84.9 mm = 3.34 inches.
Next option would be to determine the best stem angle/length, and buy it.
Another would be to first buy that Delta stem riser, and go from there.
If all else fails, I clean up this Specialized Allez, sell it, and she goes back to her original bike.
Any thoughts would be appreciated.