You can request time off under FMLA, but there is no guarantee it will be granted. FMLA allows you up to 12 weeks of unpaid, job protected leave in order to care for a "serious health condition" or serious health condition of a family member. The issue, therefore, is whether your wife's ongoing problems qualify as a "serious health condition" in her current state.
FMLA Section 101 (11) defines "serious health condition" as "inpatient care in a hospital, hospice, or residential medical care facility" or "continuing treatment by a health care provider."
See it here: http://www.dol.gov/whd/opinion/FMLA/prior2002/FMLA-67.htm
So if your best bet is to state that your wife is under "continuing treatment by a health care provider." This is the most broad category, and only requires that she be incapacitated for 3 consecutive calendar days. Again, incapacitated is a gray area.
BotXXXXX XXXXXne, all you can do is request the time and see what they say. If they say no, you will have to work something else out. I do not know the nature of your job, so can't make any suggestions (none of which would carry the force of law anyway).
But court's have found that something as minor as the flu or a virus can qualify under FMLA, so I think that your wife's issues would most likely qualify.