Pouring Puzzle

You have access to a 5 litre bowl, a 3 litre bowl, a working water tap, and a drain.
How could you measure out exactly 4 litres of water?

Nora has always been 45 years older than Sid, but now the two digits in Nora's age, both prime, are the reverse of the two in Sid's age. How old is Nora?