Dear Ursa,
I have read almost all the books, if not all, of the series.
Just like you, I enjoyed very much all of them. I used to think the same, that the story could perfectly well fit in reality.
Nevertheless, it is well known today that Neanderthal was more adapted to a cold climate and had less melanine to block sunlight. So they were lighter than Cro Magnon, which Mrs. Auel describes as blond people. I think that the idea should be reconsidered because Cro Magnon lineage was descendent directly from Africa and their skin color should be, by the moment they interbred with Neanderthal in the Fertile, much darker than that of Neanderthal.
I make this comments because occidental scientist used (I say used although many of them still think the same way) that Neanderthal were inferior race and have the idea that the blond people race survived while the inferiors Neanderthal couldn't make it. Now we know that Eurasian and American aborigin have at least 2% of Neanderthal blood or genes in their genome. I'm so in love with Neanderthal that I like to defend them. If you could read https://steemit.com/neanderthalensis/@jfparr/neanderthal-and-homo-sapiens-hybridation you would understand what I mean.
Unfortunately, archeological information at the time Mrs. Auel wrote some of her books was not as rich as today and genetic studies as genome sequencing were in process. By that time she really exhausted all sources of information and did a beautifull and exciting writing.
Yours truly,
JFParra