Dear M. M,
I'm new to Mamasource & haven't ever responded to a question (maybe because I have so many of my own!!) but felt compelled to reach out to you. I, too, have 3 children -2 biol. (9.5 & 8) & one 6.5 yr old adopted at 3. Although not a psychologist, professional child educator, pede, etc., I did stay at a Holiday Inn Express last night so therefore am an expert at all things for this one day.
Seriously, I don't think there's 'normal' for any skill at any age. Certainly there are milestones children should be reaching by certain ages, and your pede can wisely guide you on these matters. I do believe expecting a 3 year old to be able to trace letters is a little above & beyond, though certainly some 3 yr. olds can even write their own name. None of mine could at that age, & my two oldest now read 3-4 grade levels above their peers & my youngest is learning to read in K & still writing some letters backward (expected through 2nd grade!!!)
With all three of mine we focused on modeling the skills we wanted them to learn - reading, writing, social engagement, etc. - in the most fun ways we could. Keep a stack of paper on the kitchen table and a cup of crayons, pencils, markers (washable!!!) at all times. While you're cooking, feeding Coop, whatever, encourage James & Nathanael to color you a picture, or Daddy, or Grandma, whoever. Then PUT IT UP on the fridge, your bathroom mirror, etc. We have a bulletin board for each child going up our staircase where we display their work - art, math test, whatever. Kind of their own 'brag board'. My s-i-l, mom of 3 & pede nurse always thought coloring books didn't promote as much creativity as plain paper but I think the development of fine motor skills that 'coloring between the lines' prompts is as necessary as free expression. You can also have N draw something & J color it in. Anything you do with them they'll want to do even more of - read to them, paint with them, give them a bucket of water, paintbrushes & go paint the side of the house or driveway with them. Wash the car, focusing on swirling to the right or left, only washing the top half of the door, etc.
The most important thing, to me, is relax. ENJOY them, because before you know it ... And especially parenting 3 so close in age, & so suddenly, is going to challenge every fiber of your being at times. But it's so worth it. Pay close attention to Nathanael so he doesn't feel lost between the 'boss' and the 'baby'. There's a great book by Gary Chapman titled The Five Love Languages of Children which helps you determine how best to reach each child individually, whether the language that best communicates your love for them is gifts, time spent together, words of affirmation, etc. This will help while you figure out each child, as well. Other resources I found very helpful were Touchpoints by Brazelton & anything by Dr. James Dobson, esp. on raising boys.
Be well & God bless you in this most wonderful of journeys. I'm a little envious -- 3 gorgeous boys for you. How fabulous.
-S.