Orthodox Jewish writing
Ishut - Chapter Eleven
"When a girl of less than three years of age engages in sexual relations, even when her partner is an adult male, she [is entitled to] a ketubah of 200 [zuz]. Ultimately, she will heal and be a virgin like all others."
Orthodox Jewish writing
Ishut - Chapter Eleven
"Similarly, when a boy below the age of nine engages in sexual relations with an adult woman, she [is entitled to] a ketubah of 200 [zuz], as if she had never engaged in relations.6 For it is only after a boy reaches the age of nine years and one day that relations with him are of consequence. Before that age, they are of no consequence."
Jews marry mentally incompetant people
Orthodox Jewish writing
Ishut - Chapter Eleven
"4
Whether a virgin is a bogeret,7, blind,8 or an aylonit,9 she [is entitled to] a ketubah of 200 [zuz]. By contrast, no provision was made for a ketubah for a woman who is a deaf mute or mentally incompetent. [The rationale is] that no provision has been made for the marriage of a mentally incompetent woman at all."
I'm surprised that doesn't apply to all women, given that they are all mentally incompetent
Jews marry mentally incompetant people
https://web.archive.org/web/20211208015107/https://www.chabad.org/library/article_cdo/aid/952885/jewish/Chapter-Eleven.htm
Orthodox Jewish writing
Ishut - Chapter Eleven
"When a man marries a woman who is a deaf mute or mentally incompetent and writes her a ketubah for 10,000 [zuz], the obligation is binding"