1,530. Who Gets a Kesubah of 100?

Hilchos Ishus 11:1

Let’s say that a man marries a virgin who was widowed, divorced or who performed chalitzah (the shoe-removal ceremony). If she was widowed, divorced or performed chalitzah after eirusin (i.e., just the first part of marriage), her kesubah is the standard 200 zuz. However, if she completed the marriage, her kesubah is 100 zuz. Once she has been married, she is the same as a non-virgin. The same is true if a man marries a virgin who was freed from indentured servitude, converted or taken captive. If she was freed, converted or redeemed from captivity before reaching the age of three years and a day, her kesubah is 200 zuz; after that age, it is 100 zuz.

Hilchos Ishus 11:2

The Sages set the aforementioned kesubos at 100 zuz because of the legal presumption that a married woman will engage in marital relations; a similar presumption is made about indentured servants, idolators and those held captive. Accordingly, they instituted the kesubah in such cases at 100 zuz. Despite their individual biological realities, these women have the same legal status as non-virgins.