Two (at least) trains of thought on that. If you were lights out better than you've ever played it might be better to leave well enough alone; on the other hand if you were just good I might be tempted to show up on the second day. Couple of reasons:
1) Shows interest in the team. Any player who keeps coming to tryouts again and again is going to be noticed, and may just land a position because of her sheer determination to be noticed. I know one girl on one of our younger teams tried out 4-5 times before the coach said, in essence, if she's that determined to make the team, and given that she has the raw talent but not the polish, I'll take a chance on her. Another story along these lines, I had a girl that tried out for my team 3 years in a row, attending multiple tryouts each time, and was one of my last cuts every time; she came back the 4th time and while I didn't have a spot for her on my team at the time, I had no hesitation in recommending her to my other team in the age group given the improvement I had seen and knowing her determination to make one of our teams.
2) Gives you another chance to evaluate the coaching staff and possibly the players and parents. Where your daughter plays is an important decision, and knowing more about the staff and families on the team is always a good thing. You'll be in close proximity to them for at least the better part of the summer, and you'll need to decide whether or not that's viable.
