M. Gillenormand and Daughters

To summarize, M. Gillenormand is Marius's grandfather. He forced Colonel Pontmercy to give Marius up to M. Gillenormand. M. Gillenormand loved Marius, but showed it to him be arguing with him and being rough. He is strongly against Napoleon, which is at the core of the argument between himself and Colonel Pontmercy, and in an argument about Napoleon Marius leaves (much to M. Gillenormand's dismay and sorrow).
The entire second book of "Marius" is dedicated to M. Gillenormand, and can be read here.
(it tells some stories and characterizes him)

M. Gillenormand only had two children--both girls. One was by his first wife who later died. Ten years later, by his second wife, he had another daughter; Marius's mother.

"In their youth they had borne very little resemblance to each other, either in character or countenance, and had also been as little like sisters to each other as possible. The youngest had a charming soul, which turned towards all that belongs to the light, was occupied with flowers, with verses, with music, which fluttered away into glorious space, enthusiastic, ethereal, and was wedded from her very youth, in ideal, to a vague and heroic figure. The elder had also her chimera; she espied in the azure some very wealthy purveyor, a contractor, a splendidly stupid husband, a million made man, or even a prefect...—all this had created a whirlwind in her imagination. Thus the two sisters strayed, each in her own dream, at the epoch when they were young girls. Both had wings, the one like an angel, the other like a goose.No ambition is ever fully realized, here below at least. No paradise becomes terrestrial in our day. The younger wedded the man of her dreams, but she died. The elder did not marry at all."