I would tell the baby's mother as you are contagious just before the spots come out until the spots have dried. Incubation period is about 2 weeks. Buy some Poxclin ready to put on the spots! Is fabulous (I speak from experience using it on me as DD and I had it at the same time). Really cools and soothes the itchy feeling, isn't messy and no scars.
Looks like it, although would expect them on torso. If you can find a chemist today get Poxclin mousse. Bit expensive but really soothes the itch when it gets bad. Also make sure piriton and calpol stocked up. Bicarbonate or oats in bath also good.
As others said most infectious 2 days before spots until last one crusted so definitely tell friend and get DH checked out if exposure dangerous for him.
With my DD days were ok but nights were miserable. Good luck
Have you anyone from an older generation who can safely take a look (grandparent /neighbour, etc)? My friend who is a GP says she always asks this when she gets a phone call about chicken pox as the rash is quite distinctive and if granny thinks it is chicken pox, it invariably is.
In an abundance of caution, I'd ring the newborn's parents anyway just in case.
You will know by tomorrow. Chicken pox escalates pretty quickly. They aren't fluid filled at the very beginning so that alone doesn't rule it out but bites definitely possible at this time of year. Fingers crossed.