Answer:

Then God blessed them, and God said to them, “Be fruitful and multiply . . . .” (GENESIS 1:28).

ROMANS 3:235:12

Olivia, let’s look at what the Bible says to find an answer. Our verse says that God told Adam and Eve to be fruitful and multiply. In other words, they were supposed to start a family in the Garden. But the Bible also indicates that they had to leave before they had any children. 

You see, the Bible tells us that all men are born with the sin of Adam. If Adam and Eve had started their family in the Garden, their children would not have been born in sin or affected by Adam’s sin. So, I think they may have been in the Garden only a few days before they sinned and God made them leave.

Source: https://answersingenesis.org/kids/adam-and-eve/how-long-were-adam-and-eve-in-the-garden-of-eden/