Your initial instincts were better. It's about time she came home.
It is a subjunctive. But better would be
Yes, she should be home by now.
When your wife or daughter finally arrives, very late, then you would say:
It's about time she came home!
EDIT: You would exclaim the above only after wife|daughter had finally gotten home because it means The person has done what was expected of him or her (in this case, gotten home) but has taken a very long time to do it. Another example: diner at a restaurant waiting a very long time for the waiter to come over to his table. Waiter finally arrives. Diner says curtly:
It's about time you came over! or It's about time you waited on me!
The Sun-Times example We did the documentary about four years ago. It's about time to go back and do a follow-up. has an infinitive "to go" after "it's about time" whereas your sentence has a past-tense "came" (acting in a subjunctive role). The Sun-Times scenario is not an analogue for your situation.
The follow-up is due. Your wife|daughter is overdue.
If the documentary producer wanted to convey the idea that the follow up ought really to have been done long before now, that too much time has elapsed, he would say:
It's about time we went back and did a follow-up.
EDIT 2:
And to confuse things even further, intonation pattern can change the meaning.
It's about time she came home!
means she has not yet arrived and is long overdue.
It's about time she came home!
means she has finally arrived home.