Miriam, the "first lady of Israel", was the sister of the Biblical Moses and Aaron, mentioned first in Exodus 15 and again in Numbers 12. She was a prophetess, filling a role nearly the equal of her brother and high priest Aaron.
In some Jewish traditions, she is specified as being seven years older than Moses and the one responsible for suggesting that Moses' own mother serve as his midwife after he was discovered in the Nile River by the Egyptian princess (Exodus 2:5-9). It is also said that because of Miriam's righteousness, a well followed the Israelites through the desert until she died outside of Canaan (Numbers 20:1-2). In a bit of irony, her name actually means "bitter waters."
In the animated movie "The Prince of Egypt", she was the short curly-haired woman in the red dress speaking with Sandra Bullock's voice.