Urdu writes right-to-left. The first letter your child draws is teaching them the direction of the page itself, not just the shape of alif. Sit on their right side so your hand does not block the line they are pulling toward. The stroke timing here is approximate; what matters is that the pen starts at the top and ends at the baseline in a single confident pull.

Praise the act of starting. The first alif your child draws is the moment they choose to enter the script. The line does not need to be smooth yet, it needs to be theirs.