For federal purposes, the winnings of $900 are reported on the 1040, Line 21, and the losses up to the amount of winnings, $900, may be claimed on Schedule A under Other Miscellaneous Deductions; the remaining $40 may not be claimed.
half-sister - a sister who has only one parent in common with you. half sister, stepsister. sis, sister - a female person who has the same parents as another person; my sister married a musician.
A sibling is your brother or sister. It's that simple. The word sibling once meant anyone who is related to you, but now it's reserved for children of the same parent or parents. It is a word that was once out of use but then brought back into English in the early 1900s as a useful word in anthropology. If you and your brother fight all of the time, your parents might call it sibling rivalry. You might just call him annoying and run from the room.