I can try! it’s gonna be veeerrry rambly but I’ll try!
This is a concept that Hugo mentions a few times, that Valjean loves Cosette like or as a mother would, as well as like a father:
… (Valjean) felt inward yearnings, like a mother, and did not know what they were, since the strange and great motion of a heart beginning to love is incomprehensibly sweet. (2.4.3, FMA)
When she was dozing at night, before going to sleep, since she had no very clear idea of her being Jean Valjean’s daughter, and that he was her father, she imagined that her mother’s soul had passed into this good man and come to live with her.
When he sat down, she would rest her cheek on his white hair and silently drop a tear, saying to herself “Perhaps this man is my mother!” (4.3.4, FMA)Hugo says this, of course, because he thinks there’s a difference in the love of a father and the love of a mother.
Under a cut for length and discussions of canon era and canon era relevant Gender Issues: