My daughter and I hunt with regular BDU’s and we’re looking so warm base layers that aren’t too bulky so that they’ll fit under our pants and jacket and don’t restrict movement, but will retain heat well when we are sitting still in the stand.

The thermals at Walmart are junk and my brown military issue wool sweater works well for me, but we need something for our legs and feet and her abdomen (she’s nine). What can you guys recommend?

Minus 30 merino. Icebreaker is good as well but a bit more expensive.

I’ll second wool.  I have a midweight set from midway, was a real game changer for me.

Any wool/wool blend options that won’t have my daughter scaring everything within 100 miles off because of itching/scratching?

Google “US Army Waffle top and bottom.”

It’s the current mid-weight thermals issued, and they are honestly some of the best I’ve used. Can be had for about $30 per item, comes in all kinds of sizes. Warm and breathable.

Merino wool

I'm pretty warm blooded so what works for me might not work for you or your daughter.  I have friends who dress like Randy from the "Christmas Story" and still complain about being cold.  They freak out when we head out and i'm not wearing all my snivel gear.  

I use a combination of gear depending on what the terrain is.  I usually don't like having anything on my legs unless i'm going to be sitting.  I overheat if I have any type of thermal or long underwear on my legs while walking.  I found a pair of Kuiu base layer pants that only go down to the tops of your boots if you're wearing a 10" hunting boot.  They have full length zippers on both sides so you can drop your pants quickly and zip them on or off without having to take off your boots.  I like to use them when i'm on the ATV riding to my hunting spot in the mornings or on the way back after dark.  
For my tops I have some of the Under Armor gear that I layer.  I have some of the thicker tight fitting long sleeves that I wear and then usually use an Army Poly Pro top or a Cabela's Waffle top style zip up shirt.  I then wear my BDU top.  I have a Goretex jacket to wear when it's really bad weather.  Most of the time I don't need anything other than what I described.
I wear wool socks and have a couple pair of Danner boots and a pair of Crispi boots.  None of them have a lot of insulation in them because my feet sweat more in insulated boots and then end up cold.

I prefer synthetic base layers. Under Armor 1.0-4.0 base layers. I wear the 1.0 from about 15 or 20 degrees up to the 40's. The 2.0 system from 0 to 15, maybe the 3.0 here depending on wind, sit time etc.

I like the Duke longjohn and matching longsleeve. I also exclusively wear their compression boxers year round. Expensive but they last and function. The warming layers from rural king are pretty good for the money. I had got some Dickies brand stuff and it was trash.

+1 to usgi "waffle", amazingly warm, but I'd consider it a mid-layer. The polypropylene single ply stuff is the actual base layer.

I also started wearing my rain gear as a shell. Even if it's dry out, it breaks the wind.

Don't forget bibbs need to go up above the belt line or you'll end up with a cold back. Every time. At least use a suspender with your leg wear. Also helpful to hike them up high and as snug as you can to the crotch for added mobility.

I bought some LL Bean merino wool base layers this year that are at really good and fairly inexpensive (compared to others) wool option. I like wool because it doesn’t carry scent. I hang it up after each hunt and there is no smell the day after. It’s nice to not have to wash between every hunt.

Merino wool. Buy once cry once.

www.firstlite.com

The new merrino wool is quite comfortable.  My first wool base layer was an Icebreaker top I got offseason off fleabay.  I've been disappointed with every other base layer since.  It is literally the warmest, softest, most comfortable piece of clothing I've ever owned.

Look for the blend of wool/polyester.  Cheaper stuff is only 20/80.  Omniwool and i think Smart wool are lower end.

The midway pieces are good for the price.

On cold days I'll throw a waffle type top on the base layer under my coat.

Timely, my patagonias are toast.  May order some of the UA system.