What are the rights of a wife/children over her husband's earnings under the Islamic Jurisprudence?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

A husband is obliged to spend on his wife in a reasonable way. So, he has to provide her with food, clothes, house etc.

Allah Says (what means): {Let a man of wealth spend from his wealth.} [Quran 65:7]

The Prophet was asked by a man: “What is the right of the wife of one of us over him?” He replied: “Feed her whenever you feed yourself, clothe her whenever you clothe yourself; do not beat on her face; do not abuse her and do not separate yourself from her except inside the house.” [Abu Daawood]

Likewise, a father is responsible for bearing the expenses of his children. Allah Says (what means): {Upon the father is the mothers' provision and their clothing according to what is acceptable…} [Quran 2:233]

Moreover, the Prophet said to Hind : “Take what is reasonable and sufficient for you and your sons.” [Al-Bukhari and Muslim] [as her husband was very stingy]

According to the majority of Muslim scholars, when a male child becomes pubescent, or a female child gets married, their father is no longer responsible for spending on them if they are able to earn for themselves; otherwise, he has to support them.

Allah knows best.