You're welcome to check the inventory of the female next time you play then, and tell us the results.
Look, I've tried to be diplomatic. I mentioned that it was my understanding (=I don't claim to have perfect understanding) that they carried them, and provided an example (blocking with babies) on why I thought this way. I also remember some old stories that say that female melee squad members won't equip shields if they're carrying a baby etc... not that shields technically need a free hand. Now I'll admit that the baby doesn't show up in the mother's inventory, so it's not exactly like carrying an item, but hey, the dwarven inventory code probably wouldn't have allowed that directly anyway, without a workaround of some degree.
You've mainly kept stonewalling me by repeating various relatively terse variations of the first sentence in the quote below. The 2nd sentence of the quote below being the only exposition on what this means or where this is deduced from.
Babies are treated as mounting the mother in combat. That includes not being the primary target unless the mother is distracted.
Now, I'm not really that interested in continuing this argument/discussion any further (keeping in mind that just repeating the same statement without providing any justifications doesn't really qualify as either), so I guess I'll just sum this up by pointing out that I have now mentioned a couple of examples of item/shield-ish behaviour occurring, and you've presented one example of rider-type behaviour. Unless one or the other is proved to be false, my best guess for now is that babies are a special case which has elements of both. It does seem like the kind of thing that would warrant a special case, although carrying wounded dwarves, or in the next release probably also other fortress citizens, might well use the some or all of the same code as babies.
I don't think anything that pisskop wrote was intended to be inflammatory, his posts were civil as well. I mean, you only even wrote two posts before this rant (unless you deleted some), so this might be a slight overreaction... Regardless, it should be simple to figure out the answer.
Anyway, the cruelest act of Armok I've ever witnessed was thus: A Forgotten Beast made of some type of metal or other hard material (...chitin?) attacked my fortress from the caverns. I sent my heavy infantry to do battle, not realizing this FB was nearly indestructible. My militia at the time had 8 "hardened warriors" and my legendary speardwarf captain, Ulysses, with 95 kills. Well, wouldn't you know it, the 8 militiamen die almost immediately, but Ulysses was a legendary dodger and was able to survive.
He fought the mighty foe for multiple months, eventually slaying it, losing fingers, teeth, and an ear in the process. After the battle, a lowly peasant begins dragging Ulysses, badly injured and bleeding out, to the hospital. This too took almost a month, because he was originally in the caverns and my hospital is in a tower on the surface. I desperately needed to keep this dwarf alive to prevent a tantrum spiral (plus he is my only military dorf at this point). I ensured the hospital would be stocked when he got there, I turned off all other labors on my Chief Medical Dwarf, and I made 2 dwarves into "nurses" (turned off all labor other than patient care). So, after months of agonizing over his well-being, the peasant finally arrives at the hospital with Ulysses in tow.
Ulysses promptly dies of thirst.
Edit: Another similar tragedy. A titan attacks my fort from the surface, and I turn on the emergency burrow. I always lure one dwarf into the lever room and lock the door, so that they can pull the lever to the front gate as soon as all my surface dwarfs are inside. I trap Urist 1 in the lever room and wait for Urist 2 to make it back inside my fort. Urist 2 is being closely pursued by the titan, but has enough of a head start that I am confident he can make it in time.
Hooray! Urist 2 makes it over the drawbridge just in time. Time to pull the lever! Oh wait, the game paused, that means its autosaving...Spring has arrived!
Upon unpausing, I get the message: "Urist 1 has died of old age"... The same Urist 1 that was supposed to pull the lever...
The titan spared no one.