I know there's some rule about having someone actually stay awake...I will defer to kim2538's post about it being for 4+ children, since I don't know for sure. That means, not asleep in the same room, but actually awake. Still, taking in 3 kids could make a big difference to someone.
Your wife will probably want to quit her day job, though...it's a lot of work to do both. But she can decide that after she gets into it.
The most time consuming thing is getting the fingerprint check back on all the adults in the household, plus any assistants. All the rest, training and so forth can take place while you are waiting for that. Once the prints come back the Office of Child Care will order a fire inspection and set up their own inspection.
Fingerprint check depends on how backed up things get. Could be 3-4 weeks, could be a couple of months.