Malu's Wolf by Ruth Craig

Great story about a stone-age girl breaking taboos... and having to survive on her own. Based on real archaeological sites & artifacts.
Available at Amazon US in paperback, hardcover & library binding.

Dar and the Spear-Thrower by Marjorie Cowley

The story of 13 year old Dar, who lived in southern France during the last Ice Age.
Available at Amazon US in paperback & hardcover. (Note: per Marjorie, there is a free Teacher's Guide available for the asking. I haven't been able to get in contact with her or her publisher to find out HOW to get it, however!)

Anooka's Answer by Marjorie Cowley

Anooka lived about 12,000 years ago and is faced with problems due to her unusual talent for forming clay animals. Available at Amazon US in paperback & hardcover.

Maroo of the Winter Caves by Ann Turnbull

Maroo and her younger brother are forced to travel for help in a blizzard during the last Ice Age. Available at Amazon US in paperback & hardcover.