All you need to do to maintain a current license is to file for renewal before it expires (usually every two years) and to complete your state's required continuing education units. You can get CEU's online, from home. Medscape is a free site that offers many free CEU's. You can also attend educational seminars and conferences.
You could do telephone triage from home, but someone would have to watch the baby while you were working. Your BON can tell you if it qualifies as work experience. My state has a practice requirement, but nursing informatics doesn't count toward the requirement.
Would it be possible to work per-diem, every other weekend, or something else minimal to keep your foot in the door? I don't know how you feel about home health, but it can be very flexible.
400 hours in four years is not many. Just enough to be a PIA. Some bean-counting admin person who doesn't understand the nature of the work thought of that. Considering that each year the staff in my hospital, at least, has some ridiculous number of education and skills fairs and stuff ongoing all year long, you'd have to put in about 400 (with education time and driving time, etc) just to keep your annual requirements up to date for those four years, I think. What a hassle.
Find out exactly what your state considers acceptable. I wish you luck.