Most kids tie shoes between 5 and 6½. Don't expect mastery before 5; don't ignore it after 6½.
The screener hands the child a shoe with laces — sometimes on the foot, sometimes off — and says, "Can you tie this for me?" Some give one attempt with no demonstration. Others demonstrate once.
Shoe-tying integrates three things at once: bilateral hand coordination, multi-step sequencing, and the patience to stay with a fine-motor task that isn't immediately rewarding. It's a stack — fail it and the question is which layer is missing.
Start with bunny-ears, not the loop-around method — it's symmetric, which makes it easier to remember. Use two-color laces for the first two weeks; it removes the "which lace did I just have" problem. Practice with the shoe off the foot first, on a flat surface. Ten minutes a day is enough. Most children get it inside three weeks.
She ties her own shoes, on her own feet, on the floor, without you in the room, three mornings in a row. The bow holds through one walk. That's mastery for a screener's purposes.
Three weeks of daily ten-minute practice and she's still not getting it — that's a real signal. Not a panic signal; a take-it-seriously signal. The likely culprits are bilateral coordination (occupational therapist) or sequencing and working memory (developmental pediatrician). Bring video of her trying. Bring the dates you practiced. Skip the apologizing.