First, practicing under unclear situation is good training for your kid's growth, in chess and in real life. S/he should learn to take some risk and learn to handle complex issues. It takes bravity, patience, and time. If s/he can get used to survive in such difficult situations, s/he will be able to handle anything in life.
Second, when the position is still complex and unclear, anything can happen. Your opponent may not play perfectly as you expect, so there is a chance for you to win.
Third, your opponent is offering draw, which means s/he has already been defeated psychologically. Most times if your opponent is under attack, or under time pressure, s/he will not be able to defend accurately, so you should have higher probability to win. So why stop there?
Four, you have paid entry fee for the practice opportunity, you may still have several hours until next round, why do you want to take a draw to waste some practice time? To the extreme, you can take a draw before the first move. It is equal. Then why do you play in the first place?
The only exception for taking a draw is if you are guaranteed for the first place title in an important tournament with a draw. If it's not first place, then you should continue. There was an example that a girl took a draw, thinking she should at least get silver medal, but in the end she got fourth place because of tiebreak. If she won, she would get the gold medal. It's pity to miss the chance to become a world champion.